Telex VIP sent with English obscenity (9)
I believe the answer is:
expletive
'obscenity' is the definition.
(thesaurus)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for expletive that I've seen before include "oath" , "Dirty word" , "I expel vet with obscene exclamation" , "Swear word" , "Four-letter word" .)