Where Americans go around noon (3)
I believe the answer is:
can
'where americans go' is the definition.
(US term for toilet - somewhere to 'go')
'around noon' is the wordplay.
'around' becomes 'ca' (circa).
'noon' becomes 'n' ().
'ca'+'n'='CAN'
(Other definitions for can that I've seen before include "John" , "May" , "Cooler" , "(Tin) container" , "Tin; be able to" .)