Trim carry bags carry W (6)
I believe the answer is:
beluga
But I can't explain it at all! Could you help me understand?
(Other definitions for beluga that I've seen before include "Could a bugle be a source of caviar?" , "Small white whale; type of caviar" , "Large Russian sturgeon" , "'Russian sturgeon, source of caviar (6)'" , "Large sturgeon, source of ..." .)