Crushes record held by Manx cat (5)

'crushes' is the definition.
(as in crushing into pulp)

'record held by manx cat' is the wordplay.
'record' becomes 'LP' (abbreviation for long play record).
'held by' means one lot of letters goes inside another.
'manx' means to remove the last letter (Manx cats have no tail).
'cat' becomes 'puss' (puss is a kind of cat).
'puss' with its final letter taken off is 'pus'.
'lp' placed into 'pus' is 'PULPS'.