(idiomatic, anapodoton) Used to characterize a look of strong hostility

(logic, mathematics) Is equivalent to; implies and is implied by; is true and false in the same cases as. / (by extension, informal) If, with added intensity

Initialism of interactive fiction. / Initialism of impact factor. / (biochemistry) Initialism of intermediate filament. / (electronics) Initialism of intermediate frequency.

(idiomatic) If it makes no difference; if nobody minds; if it doesn't bother anyone.

Regardless of whether; irrespective of (something happening or being the case). / Even though

(idiomatic) Ellipsis of if the shoe fits, wear it.

If you cannot handle the pressure, you should not remain in a position where you have to deal with it.

As though; in a manner suggesting. / In mimicry of.

If your adversaries are stronger than you, it is better to join their side.

(idiomatic) Refers to something that the speaker deems highly unlikely.