[fourth world] {n.}, {informal} The poor nations of the world, as […]

[fourth-class(1)] {adj.} Belonging to the fourth class of mail. * /The […]

[fourth-class(2)] {adv.} By fourth-class mail. * /How did the company mail […]

[fowl] See: [NEITHER FISH NOR FOWL].

[fox and geese] {n. phr.} A tag game in which the […]

[fraidy-cat] or [fraid-cat] or [scaredy-cat] or [scared cat] {n.}, {informal} A […]

[frame of mind] {n. phr.} One's mental outlook; the state of […]

[freak] {n.}, {slang} 1. A good, or well-liked person, the opposite […]

[freak out] (2) {v. phr.}, {slang} To lose control over one's […]

[freak-out] (1) {n.}, {slang} An act of losing control; a situation […]