Gathered onset of death follows dish laced with drug (7)
I believe the answer is:
pleated
'gathered' is the definition.
(thesaurus)
'onset of death follows dish laced with drug' is the wordplay.
'onset of' suggests taking the first letters.
'follows' is a charade indicator (letters next to each other).
'dish' becomes 'plate' (plate is a kind of dish**).
'laced with' is an insertion indicator (I've seen this in other clues).
'drug' becomes 'e' (e is another name for ecstasy).
The first letter of 'death' is 'd'.
'plate' enclosing 'e' is 'pleate'.
'd' put after 'pleate' is 'PLEATED'.
(Other definitions for pleated that I've seen before include "Folded and stitched" , "With folds sewn in" , "Given creases" , "(Garment) with folds" , "Folded and sewn" .)