Dictionary.com
definitions

DOS

[daws, dos]
||
SEE MORE SYNONYMS FOR DOS ON THESAURUS.COM

noun Computers.

any of several single-user, command-driven operating systems for personal computers, especially MS DOS.

Origin of DOS

d(isk) o(perating) s(ystem)

DOS

Department of State.

DoS

[daws, dos, dee-oh-es]

Computers. denial-of-service: DoS protection for web servers.

do

1
[doo; unstressed doo, duh]

verb (used with object), present singular 1st person do, 2nd do or (Archaic) do·est or dost, 3rd does or (Archaic) do·eth or doth, present plural do; past singular 1st person did, 2nd did or (Archaic) didst, 3rd did, past plural did; past participle done; present participle do·ing.

to perform (an act, duty, role, etc.): Do nothing until you hear the bell.
to execute (a piece or amount of work): to do a hauling job.
to accomplish; finish; complete: He has already done his homework.
to put forth; exert: Do your best.
to be the cause of (good, harm, credit, etc.); bring about; effect.
to render, give, or pay (homage, justice, etc.).
to deal with, fix, clean, arrange, move, etc., (anything) as the case may require: to do the dishes.
to travel; traverse: We did 30 miles today.
to serve; suffice for: This will do us for the present.
to condone or approve, as by custom or practice: That sort of thing simply isn't done.
to travel at the rate of (a specified speed): He was doing 80 when they arrested him.
to make or prepare: I'll do the salad.
to serve (a term of time) in prison, or, sometimes, in office.
to create, form, or bring into being: She does wonderful oil portraits.
to translate into or change the form or language of: MGM did the book into a movie.
to study or work at or in the field of: I have to do my math tonight.
to explore or travel through as a sightseer: They did Greece in three weeks.
(used with a pronoun, as it or that, or with a general noun, as thing, that refers to a previously mentioned action): You were supposed to write thank-you letters; do it before tomorrow, please.
Informal. to wear out; exhaust; tire: That last set of tennis did me.
Informal. to cheat, trick, or take advantage of: That crooked dealer did him for $500 at poker.
Informal. to attend or participate in: Let's do lunch next week.
Slang. to use (a drug or drugs), especially habitually: The police report said he was doing cocaine.
Slang. to rob; steal from: The law got him for doing a lot of banks.
Slang: Vulgar. to have sex with.
Informal. (usually in the negative) to act in accordance with expectations associated with (something specified): Just ignore her insults—she doesn’t do polite.

verb (used without object), present singular 1st person do, 2nd do or (Archaic) do·est or dost, 3rd does or (Archaic) do·eth or doth, present plural do; past singular 1st person did, 2nd did or (Archaic) didst, 3rd did, past plural did; past participle done; present participle do·ing.

to act or conduct oneself; be in action; behave.
to proceed: to do wisely.
to get along; fare; manage: to do without an automobile.
to be in health, as specified: Mother and child are doing fine.
to serve or be satisfactory, as for the purpose; be enough; suffice: Will this do?
to finish or be finished.
to happen; take place; transpire: What's doing at the office?
(used as a substitute to avoid repetition of a verb or full verb expression): I think as you do.

auxiliary verb, present singular 1st person do, 2nd do or (Archaic) do·est or dost, 3rd does or (Archaic) do·eth or doth, present plural do; past singular 1st person did, 2nd did or (Archaic) didst, 3rd did, past plural did; past participle done; present participle do·ing.

(used in interrogative, negative, and inverted constructions): Do you like music? I don't care. Seldom do we witness such catastrophes.
Archaic. (used in imperatives with you or thou expressed; and occasionally as a metric filler in verse): Do thou hasten to the king's side. The wind did blow, the rain did fall.
(used to lend emphasis to a principal verb): Do visit us!

noun, plural dos, do's.

Informal. a burst of frenzied activity; action; commotion.
Informal. a hairdo or hair styling.
British Slang. a swindle; hoax.
Chiefly British. a festive social gathering; party.

Verb Phrases

do by, to deal with; treat: He had always done well by his family.
do for,
  1. to cause the defeat, ruin, or death of.
  2. Chiefly British.to cook and keep house for; manage or provide for.
do in, Informal.
  1. to kill, especially to murder.
  2. to injure gravely or exhaust; wear out; ruin: The tropical climate did them in.
  3. to cheat or swindle: He was done in by an unscrupulous broker.
do over, to redecorate.
do up, Informal.
  1. to wrap and tie up.
  2. to pin up or arrange (the hair).
  3. to renovate; launder; clean.
  4. to wear out; tire.
  5. to fasten: Do up your coat.
  6. to dress: The children were all done up in funny costumes.
do with, to gain advantage or benefit from; make use of: I could do with more leisure time.
do without,
  1. to forgo; dispense with.
  2. to dispense with the thing mentioned: The store doesn't have any, so you'll have to do without.

Idioms

    do a number on (someone). number(def 39).
    do away with,
    1. to put an end to; abolish.
    2. to kill.
    do one proud. proud(def 11).
    do one's number. number(def 40).
    do one's (own) thing. thing1(def 22).
    do or die, to make a supreme effort.
    do out of, Informal. to swindle; cheat: A furniture store did me out of several hundred dollars.
    dos and don'ts, customs, rules, or regulations: The dos and don'ts of polite manners are easy to learn.
    do time, Informal. to serve a term in prison: It's hard to get a decent job once you've done time.
    do to death. death(def 15).
    have to do with. have(def 37).
    make do, to get along with what is at hand, despite its inadequacy: I can't afford a new coat so I have to make do with this one.

Origin of do

1
before 900; Middle English, Old English dōn; cognate with Dutch doen, German tun; akin to Latin -dere to put, facere to make, do, Greek tithénai to set, put, Sanskrit dadhāti (he) puts
Can be confuseddew do dew

Synonyms for do

SEE MORE SYNONYMS FOR do ON THESAURUS.COM
1, 27. act.

Synonym study

3. Do, accomplish, achieve mean to bring some action to a conclusion. Do is the general word: He did a great deal of hard work. Accomplish and achieve both connote successful completion of an undertaking. Accomplish emphasizes attaining a desired goal through effort, skill, and perseverance: to accomplish what one has hoped for. Achieve emphasizes accomplishing something important, excellent, or great: to achieve a major breakthrough.

do

2
[doh]

noun, plural dos. Music.

the syllable used for the first tone or keynote of a diatonic scale.
(in the fixed system of solmization) the tone C.Compare sol-fa(def 1), ut.

Origin of do

2
1745–55; < Italian, inverted variant of ut; see gamut
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for dos

affair, activity, dinner, celebration, slot, duty, office, spot, job, place, situation, post, role, wealth, success, accomplishment, riches, expansion, benefit, growth

Examples from the Web for dos

Contemporary Examples of dos

Historical Examples of dos

British Dictionary definitions for dos

DOS

n acronym for trademark computing

disk-operating system, often prefixed, as in MS-DOS and PC-DOS; a computer operating system

DO

abbreviation for

Doctor of Optometry
Doctor of Osteopathy

do

1

verb does, doing, did or done

to perform or complete (a deed or action)to do a portrait; the work is done
(often intr; foll by for) to serve the needs of; be suitable for (a person, situation, etc); sufficethere isn't much food, but it'll do for the two of us
(tr) to arrange or fixyou should do the garden now
(tr) to prepare or provide; servethis restaurant doesn't do lunch on Sundays
(tr) to make tidy, elegant, ready, etc, as by arranging or adorningto do one's hair
(tr) to improve (esp in the phrase do something to or for)
(tr) to find an answer to (a problem or puzzle)
(tr) to translate or adapt the form or language ofthe book was done into a play
(intr) to conduct oneselfdo as you please
(intr) to fare or managehow are you doing these days?
(tr) to cause or producecomplaints do nothing to help
(tr) to give or renderyour portrait doesn't do you justice; do me a favour
(tr) to work at, esp as a course of study or a professionhe is doing chemistry; what do you do for a living?
(tr) to perform (a play, etc); actthey are doing ``Hamlet'' next week
(tr) to travel at a specified speed, esp as a maximumthis car will do 120 mph
(tr) to travel or traverse (a distance)we did 15 miles on our walk
(takes an infinitive without to) used as an auxiliary before the subject of an interrogative sentence as a way of forming a questiondo you agree?; when did John go out?
(takes an infinitive without to) used as an auxiliary to intensify positive statements and commandsI do like your new house; do hurry!
(takes an infinitive without to) used as an auxiliary before a negative adverb to form negative statements or commandshe does not like cheese; do not leave me here alone!
(takes an infinitive without to) used as an auxiliary in inverted constructionslittle did he realize that; only rarely does he come in before ten o'clock
used as an auxiliary to replace an earlier verb or verb phrase to avoid repetitionhe likes you as much as I do
(tr) informal to visit or explore as a sightseer or touristto do Westminster Abbey
(tr) to wear out; exhaust
(intr) to happen (esp in the phrase nothing doing)
(tr) slang to serve (a period of time) as a prison sentencehe's doing three years for burglary; he's doing time
(tr) informal to cheat or swindle
(tr) slang to robthey did three shops last night
(tr) slang
  1. to arrest
  2. to convict of a crime
(tr) Australian informal to lose or spend (money) completely
(tr) slang, mainly British to treat violently; assault
(tr) slang to take or use (a drug)
(tr) taboo, slang (of a male) to have sexual intercourse with
(tr) to partake in (a meal)let's do lunch
do or do a informal to act like; imitatehe's a good mimic – he can do all his friends well
do or die to make a final or supreme effort
how do you do? a conventional formula when being introduced
make do to manage with whatever is available

noun plural dos or do's

slang an act or instance of cheating or swindling
informal, mainly British and NZ a formal or festive gathering; party
do's and don'ts informal those things that should or should not be done; rules
See also do away with, do by, do down, do for, do in, done, do out, do over, do up, do with, do without

Word Origin for do

Old English dōn; related to Old Frisian duān, Old High German tuon, Latin abdere to put away, Greek tithenai to place; see deed, doom

do

2

noun plural dos

a variant spelling of doh 1

do

3

the internet domain name for

Dominican Republic
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for dos

do

v.

Middle English do, first person singular of Old English don "make, act, perform, cause; to put, to place," from West Germanic *don (cf. Old Saxon duan, Old Frisian dua, Dutch doen, Old High German tuon, German tun), from PIE root *dhe- "to put, place, do, make" (see factitious).

Use as an auxiliary began in Middle English. Periphrastic form in negative sentences ("They did not think") replaced the Old English negative particles ("Hie ne wendon"). Slang meaning "to do the sex act with or to" is from 1913. Expression do or die is attested from 1620s. Cf. does, did, done.

do

n.

first (and last) note of the diatonic scale, by 1754, from do, used as a substitution for ut (see gamut) for sonority's sake, first in Italy and Germany. U.S. slang do-re-mi "money" is from 1920s, probably a pun on dough in its slang sense of "cash."

Online Etymology Dictionary, © 2010 Douglas Harper