Old barrel brought into bar sounding full (7)
I believe the answer is:
orotund
'full' is the definition.
(I've seen this before)
'old barrel brought into bar sounding' is the wordplay.
I cannot quite see how this works, but
'old' could be 'o' (abbreviation) and 'o' is found in the answer.
'barrel' could be 'tun' (tun is a kind of barrel) and 'tun' is found within the answer.
'bar' could be 'rod' (both can mean a pole or stick) and 'rod' is found within the remaining letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for orotund that I've seen before include "booming" , "Of speech, dignified and pompous" , "Full in sound" , "Pompous (in style)" , "Loud or pompous" .)