He has a short way to push (5)
I believe the answer is:
heave
'push' is the definition.
(I know that heave is a type of spasm)
'he has a short way' is the wordplay.
'he has' becomes 'hes' (he's).
'a short' means to remove the last letter.
'way' becomes 'ave' (abbreviation for avenue, a type of 'way').
'hes' with its final letter removed is 'he'.
'he'+'ave'='HEAVE'
'to' acts as a link.
(Other definitions for heave that I've seen before include "cast like this" , "Lift or throw with great effort" , "Produce (a sigh); retch" , "Struggle to move" , "Produce (a sigh); lift" .)