Derogatory term. Derived from the verb 'to be keen'. Usually a schoolphrase,it's a person who is desperate to get things right. Note, not necessarily a clever person, just someone who sits at the front of class and kisses the teachers ass and wants to know everything. Note, not a snobby or smartie-pants. Just a really big keenie. Can also be adapted into the adjective 'keenified' By the way, just call people it because it makes them cry. No seriously, its a general mick take in the playground, not very offensive.
'Hahaha, you asked for extra homework you keeeenie'
'You are so keenified, you just finished your work first'