The advantage gained from time at the bar? (8)
I believe the answer is:
leverage
'the advantage' is the definition.
(leverage is a kind of advantage)
'time at the bar?' is the wordplay.
'time' becomes 'age' (an age is a period of time).
'at' means one lot of letters go next to another (I've seen this in other clues).
'the bar?' becomes 'lever' (lever is a kind of bar).
'age' put after 'lever' is 'LEVERAGE'.
'gained from' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for leverage that I've seen before include "Power of achievement; (US) gearing" , "Purchase" , "Strategic advantage; large Eve (anag.)" , "Power to influence" , "Power -- advantage" .)