Under cape, am I only in underwear? (8)
I believe the answer is:
camisole
'underwear?' is the definition.
(I've seen this before)
'under cape am i only' is the wordplay.
'under' means one lot of letters go next to another.
'cape' becomes 'c' (abbreviation used on maps).
'only' becomes 'sole' (synonyms).
'c' next to 'am' is 'cam'.
'cam'+'i'+'sole'='CAMISOLE'
'in' acts as a link.
(Other definitions for camisole that I've seen before include "Woman's undergarment with shoulder straps" , "item of underwear" , "woman could wear it" , "Short sleeveless undergarment" , "Close aim (anag.)" .)