Ton pig eats new leather strip (5)
I believe the answer is:
thong
'leather strip' is the definition.
(thong is a kind of leather strip)
'ton pig eats new' is the wordplay.
'ton' becomes 't' (abbreviation).
'pig' becomes 'hog' (synonyms).
'eats' means one lot of letters goes inside another.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'hog' placed around 'n' is 'hong'.
't'+'hong'='THONG'
(Other definitions for thong that I've seen before include "Beachwear item" , "scanty garment" , "Leather whiplash" , "flip-flop" , "Thin leather strip" .)