Iron crease for Tom perhaps (6)
I believe the answer is:
feline
'for tom perhaps' is the definition.
(tom can mean a male cat)
'iron crease' is the wordplay.
'iron' becomes 'Fe' (Fe is the chemical symbol for iron).
'crease' becomes 'line' (synonyms).
'fe'+'line'='FELINE'
(Other definitions for feline that I've seen before include "Like a cat" , "Mog" , "Like a leopard, say" , "Of or like cats" , "Persian for one" .)