Dictionary.com
definitions

as

1
[az; unstressed uh z]
See more synonyms for as on Thesaurus.com
adverb
  1. to the same degree, amount, or extent; similarly; equally: I don't think it's as hot and humid today as it was yesterday.
  2. for example; for instance: Some flowers, as the rose, require special care.
  3. thought to be or considered to be: the square as distinct from the rectangle; the church as separate from the state.
  4. in the manner (directed, agreed, promised, etc.): She sang as promised. He left as agreed.
conjunction
  1. (used correlatively after an adjective or adverb preceded by an adverbial phrase, the adverbial as, or another adverb) to such a degree or extent that: It came out the same way as it did before. You are as good as you think you are.
  2. (without antecedent) in the degree, manner, etc., of or that: She's good as gold. Do as we do.
  3. at the same time that; while; when: as you look away.
  4. since; because: As you are leaving last, please turn out the lights.
  5. though: Questionable as it may be, we will proceed.
  6. with the result or purpose: He said it in a voice so loud as to make everyone stare.
  7. Informal. (in dependent clauses) that: I don't know as I do.
  8. Midland and Southern U.S. and British Dialect. than.
pronoun
  1. (used relatively) that; who; which (usually preceded by such or the same): I have the same trouble as you had.
  2. a fact that: She did her job well, as can be proved by the records.
  3. New England, Midland, and Southern U.S. who; whom; which; that: Them as has gets.
preposition
  1. in the role, function, or status of: to act as leader.
Idioms
  1. as … as, (used to express similarity or equality in a specified characteristic, condition, etc., as between one person or thing and another): as rich as Croesus.
  2. as far as, to the degree or extent that: It is an excellent piece of work, as far as I can tell.
  3. as for/to, with respect to; in reference to: As for staying away, I wouldn't think of it.
  4. as good as,
    1. equivalent to; in effect; practically: as good as new.
    2. true to; trustworthy as: as good as his word.
  5. as how, Chiefly Midland and Southern U.S. that; if; whether: He allowed as how it was none of my business. I don't know as how I ought to interfere.
  6. as if/though, as it would be if: It was as if the world had come to an end.
  7. as is, in whatever condition something happens to be, especially referring to something offered for sale in a flawed, damaged, or used condition: We bought the table as is.
  8. as it were, in a way; so to speak: He became, as it were, a man without a country.
  9. as long as. long1(def 37).
  10. as of, beginning on; on and after; from: This price is effective as of June 23.
  11. as regards, with regard or reference to; concerning: As regards the expense involved, it is of no concern to him.
  12. as such,
    1. as being what is indicated; in that capacity: An officer of the law, as such, is entitled to respect.
    2. in itself or in themselves: The position, as such, does not appeal to him, but the salary is a lure.
  13. as well. well1(def 18).
  14. as well as. well1(def 19).
  15. as yet, up to the present time; until now: As yet, no one has thought of a solution.

Origin of as

1
before 1000; Middle English as, als, alse, also, Old English alswā, ealswā all so (see also), quite so, quite as, as; cognate with Middle Dutch alse (Dutch als), Old High German alsō (Middle High German álsō, álse, als, German also so, als as, as if, because)

Synonym study

8. See because.

Usage note

As a conjunction, one sense of as is “because”: As she was bored, Sue left the room. As also has an equally common use in the sense “while, when”: As the parade passed by, the crowd cheered and applauded. These two senses sometimes result in ambiguity: As the gates were closed, he walked away. (When? Because?)
As … as is standard in both positive and negative constructions: The fleet was as widely scattered then as it had been at the start of the conflict. Foreign service is not as attractive as it once was. So … as is sometimes used in negative constructions (… not so attractive as it once was ) and in questions ( “What is so rare as a day in June?” ).
The phrase as far as generally introduces a clause: As far as money is concerned, the council has exhausted all its resources. In some informal speech and writing, as far as is treated as a preposition and followed only by an object: As far as money, the council has exhausted all its resources.
As to as a compound preposition has long been standard though occasionally criticized as a vague substitute for about, of, on, or concerning: We were undecided as to our destination. As to sometimes occurs at the beginning of a sentence, where it introduces an element that would otherwise have less emphasis: As to his salary, that too will be reviewed. As to what and as to whether are sometimes considered redundant but have long been standard: an argument as to what department was responsible. See also all, farther, like1, so1.

though

[th oh]
conjunction
  1. (used in introducing a subordinate clause, which is often marked by ellipsis) notwithstanding that; in spite of the fact that; although: Though he tried very hard, he failed the course.
  2. even if; granting that (often preceded by even).
adverb
  1. for all that; however.
Idioms
  1. as though, as if: It seems as though the place is deserted.

Origin of though

1150–1200; Middle English thoh < Old Norse thō (earlier *thauh); replacing Old English thēah; cognate with German doch, Gothic thauh

Usage note

Among some conservatives there is a traditional objection to the use of though in place of although as a conjunction. However, the latter (earlier all though ) was originally an emphatic form of the former, and there is nothing in contemporary English usage to justify such a distinction.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for as though

apparently, evidently, presumably, probably, supposedly
British Dictionary definitions for as though

as

1
conjunction (subordinating)
  1. (often preceded by just) while; when; at the time thathe caught me as I was leaving
  2. in the way thatdancing as only she can
  3. that which; whatI did as I was told
  4. (of) which fact, event, etc (referring to the previous statement)to become wise, as we all know, is not easy
  5. as it were in a way; so to speak; as if it were really so
  6. as you were
    1. a military command to withdraw an order, return to the previous position, etc
    2. a statement to withdraw something just said
  7. since; seeing thatas you're in charge here, you'd better tell me where to wait
  8. in the same way thathe died of cancer, as his father had done
  9. in spite of the extent to whichintelligent as you are, I suspect you will fail
  10. for instancecapital cities, as London
adverb, conjunction
    1. used correlatively before an adjective or adverb and before a noun phrase or a clause to indicate identity of extent, amount, etcshe is as heavy as her sister; she is as heavy now as she used to be
    2. used with this sense after a noun phrase introduced by the sameshe is the same height as her sister
preposition
  1. in the role of; beingas his friend, I am probably biased
  2. as for or as to with reference toas for my past, I'm not telling you anything
  3. as from or as of formal (in expressions of time) fromfares on all routes will rise as from January 11
  4. as if or as though as it would be ifhe talked as if he knew all about it
  5. as is or as it is in the existing state of affairsas it is, I shall have difficulty finishing all this work, without any more
  6. as per See per (def. 3)
  7. as regards See regard (def. 6)
  8. as such See such (def. 3)
  9. such as See such (def. 5)
  10. as was in a previous state
  11. as well See well 1 (def. 13)
  12. as yet up to now; so farI have received no compensation as yet

Word Origin for as

Old English alswā likewise; see also

xref

See note at like 1

as

2
noun
  1. an ancient Roman unit of weight approximately equal to 1 pound troy (373 grams)
  2. the standard monetary unit and copper coin of ancient Rome

Word Origin for as

C17: from Latin ās unity, probably of Etruscan origin

as

3
the internet domain name for
  1. American Samoa

As

symbol for
  1. chem arsenic
  2. altostratus

AS

abbreviation for
  1. Also: A.S. Anglo-Saxon
  2. antisubmarine
  3. Australian Standards

though

conjunction (subordinating)
  1. (sometimes preceded by even) despite the fact thatthough he tries hard, he always fails; poor though she is, her life is happy
  2. as though as ifhe looked as though he'd seen a ghost
adverb
  1. nevertheless; howeverhe can't dance: he sings well, though

Word Origin for though

Old English theah; related to Old Frisian thāch, Old Saxon, Old High German thōh, Old Norse thō
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 as though

though

c.1200, from Old English þeah, and in part from Old Norse þo "though," both from Proto-Germanic *thaukh (cf. Gothic þauh, Old Frisian thach, Middle Dutch, Dutch doch, Old High German doh, German doch), from PIE demonstrative pronoun *to- (see that). The evolution of the terminal sound did not follow laugh, tough, etc., though a tendency to end the word in "f" existed c.1300-1750 and persists in dialects.

as

adv.

c.1200, worn-down form of Old English alswa "quite so" (see also), fully established by c.1400. Equivalent to so; any distinction in use is purely idiomatic. Related to German als "as, than," from Middle High German also. Phrase as well "just as much" is recorded from late 15c.; the phrase also can imply "as well as not," "as well as anything else." Interjection of incredulity as if! (i.e. "as if that really could happen") is attested from 1995, an exact duplication of Latin quasi.

Online Etymology Dictionary, © 2010 Douglas Harper
as though in Medicine

As

  1. The symbol for the elementarsenic

AS

abbr.
  1. aortic stenosis
  2. auris sinistra (left ear)
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
as though in Science

As

  1. The symbol for arsenic.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Idioms and Phrases with as though

as though

see as if.

though

see as if (though).

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.