Something stretchy - it's lace, perhaps (7)
I believe the answer is:
elastic
'something stretchy' is the definition.
(I've seen this before)
'it's lace perhaps' is the wordplay.
'perhaps' indicates an anagram.
'its'+'lace'='itslace'
'itslace' anagrammed gives 'ELASTIC'.
(Other definitions for elastic that I've seen before include "Cats lie (anag.)" , "Giving" , "Flexible, adaptable" , "Able to stretch" , "Material for bands" .)