He leaves the study to walk (5)
I believe the answer is:
tread
'walk' is the definition.
(treading is a kind of walking)
'he leaves the study' is the wordplay.
'leaves' suggests deleting specific letters.
'study' becomes 'read' ('read' can be a synonym of 'study').
'the' with 'he' removed is 't'.
't'+'read'='TREAD'
'to' acts as a link.
(Other definitions for tread that I've seen before include "Walk; part of tyre" , "dance" , "Moulded part of a tyre" , "Tramp" , "Part of flight" .)