Third-person singular simple present indicative form of keep one's hair on

(medical genetics, dermatology) An extremely rare structural anomaly of the hair with a variable degree of effect, characterized by hair that is silvery, dry, frizzy, wiry, and impossible to comb.

(idiomatic) To relax and enjoy oneself.

(colloquial) Alternative form of fine as frog hair

(idiomatic) To have someone in a difficult situation in which he or she is without alternatives and can be controlled.

(idiomatic) To make a person (especially a male) stronger or more masculine or mature.

(idiomatic) To react with extreme agitation.

Synonym of hair of the dog

Third-person singular simple present indicative form of let one's hair down

present participle of let one's hair down