Jumble left in small sailing boat (7)
I believe the answer is:
clutter
'jumble' is the definition.
(synonyms)
'left in small sailing boat' is the wordplay.
I cannot really see how this works, but
'left' could be 'l' (common abbreviation) and 'l' is found within the answer.
'boat' could be 'cutter' (historical type of ship) and 'cutter' is present in the leftover letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for clutter that I've seen before include "Clog up" , "Disorderly heap" , "Confused multitude of things" , "Untidiness" , "Untidy mess" .)