Keen has 12 different meanings across 4 categories:
Noun · Verb · Adjective · Proper Noun
a funeral lament sung with loud wailing
"The mourners raised their voices in a keen as they walked through the snow-covered fields to bury their loved one."
A prolonged wail for a deceased person.
"The mourners let out a keen as they walked past the funeral procession."
In plain English: A keen is an old-fashioned word for someone who shows great enthusiasm or eagerness about something.
"The keen was the sharp sound made by the whetstone when sharpening his knife."
having or demonstrating ability to recognize or draw fine distinctions
"an acute observer of politics and politicians"
"incisive comments"
"icy knifelike reasoning"
"as sharp and incisive as the stroke of a fang"
"penetrating insight"
"frequent penetrative observations"
Often with a prepositional phrase, or with to and an infinitive: showing a quick and ardent responsiveness or willingness; eager, enthusiastic, interested.
"She was keen to learn the new software immediately."
In plain English: Keen means really excited about something and eager to do it.
"She is very keen on learning new languages."
Usage: Use "keen" before the preposition on when describing enthusiasm for an activity, such as being keen on hiking. It is often interchangeable with eager but carries a slightly more intense sense of ardor or sharp interest.
A surname.
"The Keen family has lived in this valley for five generations."
The word keen entered English in the Middle Ages with meanings like bold and brave before settling on its current sense of sharp or acute. It ultimately traces back to a root meaning "to know," reflecting an original connection between intelligence, skill, and perceptiveness.