Joke by gent is somewhat ripe (3)
I believe the answer is:
pun
'joke' is the definition.
(pun is a type of joke)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for pun that I've seen before include "Humorous play on words" , "joke" , "A play on words - not the height of wit" , "A play on words, may be funny" , "Double entendre" .)