Rubbish from Jethro Tull (3)
I believe the answer is:
rot
'rubbish' is the definition.
(thesaurus)
'from jethro tull' is the wordplay.
'from' indicates a hidden word.
'ROT' is hidden in the letters of 'jethro tull'.
(Other definitions for rot that I've seen before include "Putrefy" , "Deterioration" , "Cobblers" , "Drivel" , "Gradual decline" .)