Type of rock almost a joke (3)
I believe the answer is:
pun
'a joke' is the definition.
(pun is a type of joke)
'type of rock almost' is the wordplay.
'type of rock' becomes 'punk' (as in punk rock music).
'almost' means to remove the last letter (most of the word but not all of it).
'punk' with its final letter removed is 'PUN'.
(Other definitions for pun that I've seen before include "conceit by a wordsmith?" , "A play on words, perhaps the lowest form of wit" , "Humorous play on words" , "A play on words, may be funny" , "Double entendre" .)