Overheard couple give cash for wig (6)
I believe the answer is:
toupee
'wig' is the definition.
(I've seen this before)
'overheard couple give cash for' is the wordplay.
I cannot really see how this works, but
'cash' could be 'p' (abbreviation for pence) and 'p' is found in the answer.
'for' could be 'to' (eg both can mean 'in the opinion of') and 'to' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for toupee that I've seen before include "rug" , "Wig or hairpiece in America" , "Artificial hairpiece" , "A wig for American male" , "A man's hairpiece in America" .)