adjective, keen·er, keen·est.
- finely sharpened, as an edge; so shaped as to cut or pierce substances readily: a keen razor.
- sharp, piercing, or biting: a keen wind; keen satire.
- characterized by strength and distinctness of perception; extremely sensitive or responsive: keen eyes; keen ears.
- having or showing great mental penetration or acumen: keen reasoning; a keen mind.
- animated by or showing strong feeling or desire: keen competition.
- intense, as feeling or desire: keen ambition; keen jealousy.
- eager; interested; enthusiastic (often followed by about, on, etc., or an infinitive): She is really keen on going swimming.
- Slang. great; wonderful; marvelous.
- eager or enthusiastic
- (postpositive foll by on) fond (of); devoted (to)keen on a girl; keen on golf
- intellectually acutea keen wit
- (of sight, smell, hearing, etc) capable of recognizing fine distinctions
- having a sharp cutting edge or point
- extremely cold and penetratinga keen wind
- intense or stronga keen desire
- mainly British extremely low so as to be competitivekeen prices
- slang, mainly US and Canadian very good
- to lament the dead
- a dirge or lament for the dead
c.1200, from Old English cene “bold brave,” later “clever, wise,” from Proto-Germanic *kan- “be able to” (see can). Original prehistoric senses seem to have been both “brave” and “skilled;” cognate with Old Norse kænn “skillful, wise,” Middle Dutch coene “bold,” Dutch koen, Old High German kuon “pugnacious, strong,” German kühn “bold, daring.” Sense of “eager” is from mid-14c. The meaning “sharp” is peculiar to English: of blades and edges early 13c., of sounds c.1400, of eyesight c.1720. A popular word of approval in teenager and student slang from c.1900.
“lament,” 1811, from Irish caoinim “I weep, wail, lament,” from Old Irish coinim “I wail.” Related: Keened; keening. As a noun from 1830.