Left rascal to hobble (4)
I believe the answer is:
limp
'to hobble' is the definition.
(synonyms)
'left rascal' is the wordplay.
'left' becomes 'l' (common abbreviation).
'rascal' becomes 'imp' (synonyms).
'l'+'imp'='LIMP'
(Other definitions for limp that I've seen before include "Hanging loosely - hobble" , "without energy" , "Walk with an uneven step" , "Uneven manner of walking" , "Wanting stiffness" .)