Release charge about right (4)
I believe the answer is:
free
'release' is the definition.
(synonyms)
'charge about right' is the wordplay.
'charge' becomes 'fee' (fee is a kind of charge).
'about' means one lot of letters goes inside another.
'right' becomes 'r' (abbreviation).
'fee' going around 'r' is 'FREE'.
(Other definitions for free that I've seen before include "At large" , "Not busy" , "Liberated" , "unemployed" , "Type of tenure" .)