[sahyn-on, -awn]


Radio and Television. the opening salutation, station identification, etc., at the beginning of the broadcast day.
an act or instance of signing on.

Nearby words

  1. lofting,
  2. lofting iron,
  3. lofting, hugh,
  4. loftsman,
  5. lofty,
  6. log book,
  7. log chip,
  8. log in,
  9. log jam,
  10. log line

Origin of sign-on

First recorded in 1880–85; noun use of verb phrase sign on


[lawg, log]


a portion or length of the trunk or of a large limb of a felled tree.
something inert, heavy, or not sentient.
Nautical. any of various devices for determining the speed of a ship, as a chip log or patent log.
any of various records, made in rough or finished form, concerning a trip made by a ship or aircraft and dealing with particulars of navigation, weather, engine performance, discipline, and other pertinent details; logbook.
Movies. an account describing or denoting each shot as it is taken, written down during production and referred to in editing the film.
a register of the operation of a machine.
Also called well log. a record kept during the drilling of a well, especially of the geological formations penetrated.
Computers. any of various chronological records made concerning the use of a computer system, the changes made to data, etc.
Radio and Television. a written account of everything transmitted by a station or network.
Also called log of wood. Australian Slang. a lazy, dull-witted person; fool.

verb (used with object), logged, log·ging.

to cut (trees) into logs: to log pine trees for fuel.
to cut down the trees or timber on (land): We logged the entire area in a week.
to enter in a log; compile; amass; keep a record of: to log a day's events.
to make (a certain speed), as a ship or airplane: We are logging 18 knots.
to travel for (a certain distance or a certain amount of time), according to the record of a log: We logged 30 miles the first day. He has logged 10,000 hours flying time.

verb (used without object), logged, log·ging.

to cut down trees and get out logs from the forest for timber: to log for a living.

Verb Phrases

log in,
  1. Also log on, sign enter identifying data, as a username or password, into a database, mobile device, or computer, especially a multiuser computer or a remote or networked system, so as to to access and use it: Log in to start your work session. Log in to your account to pay your bill online.
  2. to enter or include any item of information or data in a record, account, etc.
log off/out, Computers. to terminate a session.

Origin of log

1350–1400; Middle English logge, variant of lugge pole, limb of tree; compare obsolete logget pole; see lugsail, logbook

Related formslog·gish, adjectiveun·logged, adjective




a token; indication.
any object, action, event, pattern, etc., that conveys a meaning.
a conventional or arbitrary mark, figure, or symbol used as an abbreviation for the word or words it represents.
a motion or gesture used to express or convey an idea, command, decision, etc.: Her nod was a sign that it was time to leave.
a notice, bearing a name, direction, warning, or advertisement, that is displayed or posted for public view: a traffic sign; a store sign.
a trace; vestige: There wasn't a sign of them.
an arbitrary or conventional symbol used in musical notation to indicate tonality, tempo, etc.
Medicine/Medical. the objective indications of a disease.
any meaningful gestural unit belonging to a sign language.
an omen; portent: a sign of approaching decadence.
Usually signs. traces, as footprints, of a wild animal.
  1. a plus sign or minus sign used as a symbol for indicating addition or subtraction.
  2. a plus sign or minus sign used as a symbol for indicating the positive or negative value of a quantity, as an integer.
  3. multiplication sign.
  4. division sign.
  5. a symbol, as  or !, used to indicate a radical or factorial operation.

verb (used with object)

to affix a signature to: to sign a letter.
to write as a signature: to sign one's name.
to engage by written agreement: to sign a new player.
to mark with a sign, especially the sign of the cross.
to communicate by means of a sign; signal: He signed his wish to leave.
to convey (a message) in a sign language.
Obsolete. to direct or appoint by a sign.

verb (used without object)

to write one's signature, as a token of agreement, obligation, receipt, etc.: to sign for a package.
to make a sign or signal: He signed to her to go away.
to employ a sign language for communication.
to obligate oneself by signature: He signed with another team for the next season.

Verb Phrases

sign away/over, to assign or dispose of by affixing one's signature to a document: She signed over her fortune to the church.
sign in, to record or authorize one's arrival (or departure) by signing a register.Also sign out.
sign off,
  1. to withdraw, as from some responsibility or connection.
  2. to cease radio or television broadcasting, especially at the end of the day.
  3. become silent: He had exhausted conversation topics and signed off.
  4. to indicate one's approval explicitly if not formally: The president is expected to sign off on the new agreement.
sign on,
  1. to employ; hire.
  2. to bind oneself to work, as by signing a contract: He signed on as a pitcher with a major-league team.
  3. to start radio or television broadcasting, especially at the beginning of the day.
  4. Computers.log1(def 17a).
sign up, to enlist, as in an organization or group; to register or subscribe: to sign up for the navy; to sign up for class.

Origin of sign

1175–1225; (noun) Middle English signe < Old French < Latin signum mark, sign, ensign, signal, image; (v.) Middle English signen to mark with a sign, especially the sign of the cross < Old French signer < Latin signāre to mark with a sign, inscribe, affix a seal to, derivative of signum

1. trace, hint, suggestion. 1, 4. signal. 10. indication, hint, augury. Sign, omen, portent name that which gives evidence of a future event. Sign is a general word for whatever gives evidence of an event—past, present, or future: Dark clouds are a sign of rain or snow. An omen is an augury or warning of things to come; it is used only of the future, in general, as good or bad: birds of evil omen. Portent, limited, like omen, to prophecy of the future, may be used of a specific event, usually a misfortune: portents of war.

Related formssign·less, adjectivesign·like, adjectivepost·sign, verb (used with object)un·signed, adjective

Can be confusedsign sing (see synonym study at the current entry) Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for sign on

sign on

verb (adverb)

(tr) to hire or employ
(intr) to commit oneself to a job, activity, etc
(intr) British to register as unemployed with the Department of Social Security




  1. a section of the trunk or a main branch of a tree, when stripped of branches
  2. (modifier)constructed out of logsa log cabin
  1. a detailed record of a voyage of a ship or aircraft
  2. a record of the hours flown by pilots and aircrews
  3. a book in which these records are made; logbook
a written record of information about transmissions kept by radio stations, amateur radio operators, etc
  1. a device consisting of a float with an attached line, formerly used to measure the speed of a shipSee also chip log
  2. heave the logto determine a ship's speed with such a device
Australian a claim for better pay and conditions presented by a trade union to an employer
like a log without stirring or being disturbed (in the phrase sleep like a log)

verb logs, logging or logged

(tr) to fell the trees of (a forest, area, etc) for timber
(tr) to saw logs from (trees)
(intr) to work at the felling of timber
(tr) to enter (a distance, event, etc) in a logbook or log
(tr) to record the punishment received by (a sailor) in a logbook
(tr) to travel (a specified distance or time) or move at (a specified speed)

Word Origin for log

C14: origin obscure




short for logarithm



something that indicates or acts as a token of a fact, condition, etc, that is not immediately or outwardly observable
an action or gesture intended to convey information, a command, etc
  1. a board, placard, etc, displayed in public and inscribed with words or designs intended to inform, warn, etc
  2. (as modifier)a sign painter
an arbitrary or conventional mark or device that stands for a word, phrase, etc
maths logic
  1. any symbol indicating an operationa plus sign; an implication sign
  2. the positivity or negativity of a number, quantity, or expressionsubtraction from zero changes the sign of an expression
an indication or vestigethe house showed no signs of being occupied
a portentous or significant event
an indication, such as a scent or spoor, of the presence of an animal
med any objective evidence of the presence of a disease or disorderCompare symptom (def. 1)
astrology Compare sign of the zodiac


to write (one's name) as a signature to (a document, etc) in attestation, confirmation, ratification, etc
(intr often foll by to) to make a sign; signal
to engage or be engaged by written agreement, as a player for a team, etc
(tr) to outline in gestures a sign over, esp the sign of the cross
(tr) to indicate by or as if by a sign; betoken
(intr) to use sign language

Derived Formssignable, adjective

Word Origin for sign

C13: from Old French signe, from Latin signum a sign

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 sign on
Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for sign on




An objective finding, usually detected on physical examination, from a laboratory test, or on an x-ray, that indicates the presence of abnormality or disease.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for sign on



A logarithm.



A body manifestation, usually detected on physical examination or through laboratory tests or xrays, that indicates the presence of abnormality or disease. Compare symptom.
See symbol. See Table at symbol.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Idioms and Phrases with sign on

sign on


Enlist oneself as an employee, as in Arthur decided to sign on with the new software company. [Late 1800s]


Begin radio or television broadcasting, especially at the beginning of the day, as in What time does the station sign on? [c. 1920]


In addition to the idiom beginning with log

  • log in

also see:

  • easy as pie (rolling off a log)
  • like a bump on a log
  • sleep like a log


In addition to the idioms beginning with sign

  • sign in
  • sign off
  • sign on
  • sign one's own death warrant
  • sign on the dotted line
  • sign out
  • sign over
  • sign up

, see

  • high sign
  • show signs of
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.