Men jump on one leg in uncle's place (8)
I believe the answer is:
pawnshop
'uncle's place' is the definition.
(I've seen this before)
'men jump on one leg' is the wordplay.
'men' becomes 'pawns' (pawn is a kind of man).
'jump on one leg' becomes 'hop' (I've seen this before).
'pawns'+'hop'='PAWNSHOP'
'in' is the link.
(Other definitions for pawnshop that I've seen before include "Premises for loans against personal property" , "Where money may be borrowed by depositing personal goods as security" , "Where one finds security" , "Mitigate, forgive" , "Uncle's place of business?" .)