Shirtmaker's measurement (6)
I believe the answer is:
sleeve
'shirtmaker's measurement' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sleeve that I've seen before include "Cover for arm and vinyl record" , "Cover for a gramophone record" , "Part of a shirt or jacket" , "Container for LP" , "Possibly hiding-place for ace" .)