keen

/ˈkēn/

Middle English kene brave, sharp, from Old English cēne brave; akin to Old High German kuoni brave

adjective

  1. intellectually alert : having or characteristic of a quick penetrating mind; also : shrewdly, astute

  2. extremely sensitive in perception

  3. sharply contested

a keen student

keen eyes

sharp keen acute mean having or showing alert competence and clear understanding. sharp implies quick perception, clever resourcefulness, or sometimes questionable trickiness. keen suggests quickness, enthusiasm, and a penetrating mind.

verb

  1. to make a loud and long cry of sorrow : to lament with a keen

  2. to make a sound suggestive of a loud cry of sorrow

  3. to lament, mourn, or complain loudly

a keening siren

noun

  1. a lamentation for the dead uttered in a loud wailing voice or sometimes in a wordless cry