Lad, figure out who could help you in the main? (9)
I believe the answer is:
lifeguard
'help you in the main?' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'lad figure out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'lad'+'figure'='ladfigure'
'ladfigure' with letters rearranged gives 'LIFEGUARD'.
'who could' is the link.
Can you help me to learn more?
(Other definitions for lifeguard that I've seen before include "Beach or pool employee" , "Person protecting bathers" , "beach official" .)