wit
Wit or apt means cleverness or intelligent.
A three letter word that could mean clever is sly.
SlyWit
Wit is a three-letter word that refers to both a sense of humor and cleverness.
COMINT, ELINT, and FISINT
A three letter word for cleverness and intelligence is wit.
The three later word that means view is see.
Observe means to see.
ilk
apt
Sly
din