Dollar over, young man (5)
I believe the answer is:
bucko
'young man' is the definition.
Both the definition and answer are singular nouns.
Perhaps they are linked in a way I don't understand?
'dollar over' is the wordplay.
'dollar' becomes 'buck' (slang).
'over' becomes 'o' (cricket abbreviation).
'buck'+'o'='BUCKO'
Can you help me to learn more?
(Other definitions for bucko that I've seen before include "Young Irishman" , "Fellow swaggering" , "Young lad" , "Lively young Irish fellow" , "One swaggering" .)