Hide murders cracked by Sherlock at last (7)
I believe the answer is:
doeskin
'hide' is the definition.
(thesaurus)
'murders cracked by sherlock at last' is the wordplay.
'murders' becomes 'does in' (I've seen this in another clue).
'cracked by' means one lot of letters goes inside another (inserted letters go into a gap or crack).
'at last' indicates one should take the final letters.
The last letter of 'sherlock' is 'k'.
'doesin' placed around 'k' is 'DOESKIN'.
(Other definitions for doeskin that I've seen before include "glove material" , "Type of leather" , "Leather from deer" .)