With most of extract, fill drum (7)
I believe the answer is:
pulsate
'drum' is the definition.
(thesaurus)
'with most of extract fill' is the wordplay.
'with' is a charade indicator (letters next to each other).
'most of' means to remove the last letter.
'extract' becomes 'pulp' (pulping is a kind of extracting).
'fill' becomes 'sate' (synonyms).
'pulp' with its final letter removed is 'pul'.
'pul' put next to 'sate' is 'PULSATE'.
(Other definitions for pulsate that I've seen before include "thrill" , "Expand and contract regularly" , "Throb regularly like heart" , "Produce a regular throbbing sensation" .)