Was inclined to duck into shelter (4-2)
I believe the answer is:
lean-to
'shelter' is the definition.
(I've seen this before)
'was inclined to duck' is the wordplay.
'was inclined' becomes 'leant' (I've seen this before).
'to duck' becomes 'o' (resembles zero - 'duck' in cricket).
'leant'+'o'='LEAN-TO'
'into' acts as a link.
(Other definitions for lean-to that I've seen before include "Add-on building" , "Type of shed" , "Attached outbuilding" , "Structure whose roof has only one slope" , "It's roof slants against a wall" .)