Expose yourself to hot copper close to bar (5)
I believe the answer is:
incur
'expose yourself' is the definition.
I can't tell whether this definition defines the answer.
'hot copper close to bar' is the wordplay.
'hot' becomes 'in' (both can mean fashionable).
'copper' becomes 'cu' (chemical symbol).
'close to' indicates one should take the final letters (the close/ending of).
The final letter of 'bar' is 'r'.
'in'+'cu'+'r'='INCUR'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for incur that I've seen before include "Become liable to (eg, a penalty)" , "Become subject to (something unpleasant)" , "Become subject to (penalty)" , "Fall liable to" , "Fall into - invite" .)