Yen or pound? (4)
I believe the answer is:
ache
I believe this is a double definition.
'yen' is the first definition.
(synonyms)
'pound?' is the second definition.
(pounding is a kind of aching)
'or' is the link.
(Other definitions for ache that I've seen before include "Shakespearean character" , "Nagging pain" , "Similar" , "Take an aspirin for it" , "Suffer dull pain" .)