Cheerful time at the bar! (5,4)
I believe the answer is:
happy hour
'the bar' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'cheerful time' is the wordplay.
'cheerful' becomes 'happy' (associated in meaning).
'time' becomes 'hour' (unit of time).
'happy'+'hour'='HAPPY HOUR'
'at' acts as a link.
Can you help me to learn more?
(Other definitions for happy hour that I've seen before include "Cheap time to get merry!" , "beer goes down" , "Period of cheap drinks" , "Cheap drinking time" , "pub's promotion" .)