very interested, eager, or wanting (to do) something very much:
She's a keen tennis player.
Joan wanted to go to a movie but I wasn't keen (= I didn't want to go).
keen to They were very keen to start work as soon as possible.
keen on She's keen on (playing) tennis.
UK My son's mad keen on cycling.
He's rather keen on a girl in his school (= he is very attracted to her).
extreme or very strong:
keen interest Many people are taking a keen interest (= a very great interest) in the result of the vote.
very good or well developed:
a keen sense of smell
A keen wind is strong and cold:
a keen north wind
very sharp:
a keen knife
The tribe used obsidian to cut through whale skin, as the thick skin could dull even the keenest blade within a matter of minutes.
to make a loud, long, sad sound, especially because someone has died
(esp. of emotions and beliefs) strongly felt:
a keen interest in painting
(of an awareness or ability) very developed, or (of the mind) very quick to understand:
a keen eye for detail
a keen sense of smell
eager, interested, and enthusiastic:
Theresa isn’t too keen on pets.
if competition between people or businesses is keen, they are using a lot of effort to be more successful than the others:
Some firms are diversifying their businesses in response to keen competition.
if prices are keen, they are lower and offer more value than others:
Superstores may offer keen prices that small-town shops cannot match.
very interested in something or eager to do something:
A keen member of two local investment clubs, he runs portfolios of shares for both himself and his wife.
a keen interest in sth Among the foundation's donors are corporations with a keen interest in issues before the legislature.
keen on sth Like every banker these days, he is keen on managing other people's wealth.
keen to do sth The company is keen to expand beyond the UK.