Looking embarrassed, a wife over boot (5)
I believe the answer is:
wader
'boot' is the definition.
(I have seen 'Waterproof boot ' mean 'wader' so perhaps 'boot' could also mean 'wader')
'looking embarrassed a wife over' is the wordplay.
'looking embarrassed' becomes 'red' (someone may go red when embarrassed).
'wife' becomes 'w' (abbreviation).
'over' is a reversal indicator.
'red'+'a'+'w'='redaw'
'redaw' back-to-front is 'WADER'.
(Other definitions for wader that I've seen before include "Long-legged shore bird" , "Heron, say" , "Bird such as a sandpiper or plover" , "High waterproof boot" , "Snipe maybe" .)