adjective
- of, situated, or for use under the arm or in the armpit: an underarm deodorant.
- underhand: an underarm pitch in softball.
noun
- armpit.
adverb
- underhand.
adjective
- (of a measurement) extending along the arm from wrist to armpit
- sport of or denoting a style of throwing, bowling, or serving in which the hand is swung below shoulder level
- below the arm
adverb
- in an underarm style
adj.1816, “underhand” (in reference to a style of throwing), from under + arm (n.1). First attested 1908 in dressmaking sense of “seams on the lower half of the arm-hole;” as a euphemism for armpit, it is attested from 1930s, popularized by advertisers. adj.
- Located, placed, or used under the arm.
n.
- The armpit.