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 fol. by about, on, etc., or an infinitive)

She is really keen on going swimming.

Slang . great; wonderful; marvelous.

adjective

reluctant , unenthusiastic , uninterested , blunt , dull , obtuse , pointless , idiotic , ignorant , stupid

adjective

agog , alert , animate , animated , anxious , appetent , ardent , athirst , avid , breathless , devoted , dying to , eager , earnest , ebullient , fervent , fervid , fierce , fond of , gung ho * , impassioned , impatient , intense , intent , interested , lively , perfervid , spirited , sprightly , thirsty , vehement , vivacious , warm , zealous , acid , acute , caustic , cutting , edged , extreme , fine , honed , incisive , observant , penetrating , perceptive , pointed , quick-witted , razor-sharp , sardonic , satirical , strong , tart , trenchant , unblunted , astute , bright , brilliant , canny , clever , discerning , discriminating , einstein , nobody’s fool , perspicacious , quick , sagacious , sapient , sensitive , sharp , sharp as a tack , shrewd , whiz , wise , intelligent , sharp-witted , smart , probing , mad , rabid , bursting , solicitous , thirsting , divine , fabulous , fantastic , fantastical , glorious , sensational , splendid , superb , terrific , wonderful , acrimonious , a crimonious , acuminous , analytical , appercipient , awake , bewail , bitter , boned , cunning , enthusiastic , excruciating , mordacious , mordant , piercing , piquant , poignant , pungent , ravenous , severe , vivid , wail

verb

bawl , blubber , howl , sob , wail , weep , yowl