Nonsense coming from revolutionary needing no introduction (3)
I believe the answer is:
rot
'nonsense' is the definition.
(thesaurus)
'revolutionary needing no introduction' is the wordplay.
'revolutionary' becomes 'trot' (abbreviation of Trotskyite).
'needing no introduction' means to remove the first letter.
'trot' with its first letter removed is 'ROT'.
'coming from' is the link.
(Other definitions for rot that I've seen before include "Decay - nonsense" , "Decomposition" , "Decay - rubbish" , "Informal nonsense" , "Gradual decline" .)