Baglike structure (3)
I believe the answer is:
sac
'baglike structure' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sac that I've seen before include "pocket" , "Bodily pouch" , "Pouch or bag-like structure" , "Traditional entitlement to hold court" , "Animal or vegetable pouch" .)