Captain perhaps losing a pipe and navy trousers (10)
I believe the answer is:
lederhosen
'trousers' is the definition.
(I've seen this before)
'captain perhaps losing a pipe and navy' is the wordplay.
'captain perhaps' becomes 'leader' (captain is a kind of leader).
'losing' indicates named letters should be taken away.
'pipe' becomes 'hose' (I've seen this before**).
'and' means one lot of letters go next to another.
'navy' becomes 'n' (common abbreviation eg in RN Royal Navy).
'leader' with 'a' taken away is 'leder'.
'leder'+'hose'+'n'='LEDERHOSEN'
(Other definitions for lederhosen that I've seen before include "trousers displayed" , "pants" , "Bavarian shorts with braces" , "Short leather trousers with braces" , "Bavarian leather shorts" .)