Left rascal a difficult walk (4)
I believe the answer is:
limp
'a difficult walk' is the definition.
'limp' can be an answer for 'walk' (limp is a kind of walk). I am not certain of the 'a difficult' bit.
'left rascal' is the wordplay.
'left' becomes 'l' (common abbreviation).
'rascal' becomes 'imp' (synonyms).
'l'+'imp'='LIMP'
Can you help me to learn more?
(Other definitions for limp that I've seen before include "Floppy" , "Walk badly; not stiff" , "Walk unevenly; not stiff" , "Walk with uneven gait" , "Walk with an uneven stop" .)