Naughty vet I expel for a word that's naughty (9)
I believe the answer is:
expletive
'a word that's naughty' is the definition.
I can't judge whether this definition defines the answer.
'naughty vet i expel' is the wordplay.
'naughty' indicates an anagram.
'vet'+'i'+'expel'='vetiexpel'
'vetiexpel' with letters rearranged gives 'EXPLETIVE'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for expletive that I've seen before include "Four-letter word" , "Swearword" , "I expel vet with obscene exclamation" , "oath" , "Swear word" .)