[ if ]
See synonyms for if on Thesaurus.com
  1. in case that; granting or supposing that; on condition that: Sing if you want to. Stay indoors if it rains. I'll go if you do.

  2. even though: an enthusiastic if small audience.

  1. whether: He asked if I knew Spanish.

  2. (used to introduce an exclamatory phrase): If only Dad could see me now!

  3. when or whenever: If it was raining, we had to play inside.

  1. a supposition; uncertain possibility: The future is full of ifs.

  2. a condition, requirement, or stipulation: There are too many ifs in his agreement.

Idioms about if

  1. ifs, ands, or buts, reservations, restrictions, or excuses: I want that job finished today, and no ifs, ands, or buts.

Origin of if

First recorded before 900; Middle English, variant of yif, Old English gif, gef; akin to Old Norse ef “if,” Gothic ibai “whether,” Old High German iba “condition, stipulation”

synonym study For if

1, 2. If, provided, providing imply a condition on which something depends. If is general. It may be used to indicate suppositions or hypothetical conditions (often involving doubt or uncertainty): If you like, we can go straight home. If I had known, I wouldn't have gone. If may mean even though: If I am wrong, you are not right. It may mean whenever: If I do not understand, I ask questions. Provided always indicates some stipulation: I will subscribe ten dollars provided ( on the condition ) that you do, too. Provided he goes, we can go along. Providing means the same as provided, that is, just in case some certain thing should happen: We will buy the house, providing ( provided ) we can get a mortgage.

usage note For if

If meaning “whether,” as in I haven't decided if I'll go, is sometimes criticized, but the usage is long established as standard.

Words Nearby if

Other definitions for if (2 of 2)


Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use if in a sentence

  • if-itty-teshi-mow Jays Haddee ny up-plo-now-shi-buh nays;ha!

  • It is a succession of short notes rapidly uttered, as if the bird said "if-if-if-if-if-if-if."

    A Year in the Fields | John Burroughs
  • By all the gods!if he had only known Who held him between life and death upon the Mauvais Pas!

    The Sorrows of Satan | Marie Corelli
  • Sir S. returned the nod stiffly, with an "I-wonder-if-I-really-do know-you,-or-if-this-is-a-trick-to-claim-acquaintance?"

    The Heather-Moon | C. N. Williamson and A. M. Williamson
  • if so, I knew him now for a fiend in very truth!if burning horror and endless shame can so transfigure the soul of man!

    The Sorrows of Satan | Marie Corelli

British Dictionary definitions for if (1 of 2)


/ (ɪf) /

  1. in case that, or on condition that: if you try hard it might work; if he were poor, would you marry him?

  2. used to introduce an indirect question. In this sense, if approaches the meaning of whether

  1. even though: an attractive if awkward girl

    • used to introduce expressions of desire, with only: if I had only known

    • used to introduce exclamations of surprise, dismay, etc: if this doesn't top everything!

  2. as if as it would be if; as though: he treats me as if I were junior to him

  1. an uncertainty or doubt: the big if is whether our plan will work at all

  2. a condition or stipulation: I won't have any ifs or buts

Origin of if

Old English gif; related to Old Saxon ef if, Old High German iba whether, if

British Dictionary definitions for IF (2 of 2)



/ electronics /

abbreviation for
  1. intermediate frequency

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

Other Idioms and Phrases with if


In addition to the idioms beginning with if

  • if anything
  • if at first you don't succeed, try, try again
  • if it ain't broke don't fix it
  • if only
  • if the mountain won't come to Muhammad, Muhammad must go to the mountain
  • if the shoe fits, wear it
  • if wishes were horses
  • if worst comes to worst
  • if you can't beat 'em, join 'em
  • if you can't stand the heat, get out of the kitchen

also see:

  • as if
  • damned if I do, damned if I don't
  • make as if to
  • no ifs or buts
  • nothing if not
  • (if) push comes to shove
  • what if

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