Run into small building, feel pain (4)
I believe the answer is:
hurt
'feel pain' is the definition.
(synonyms)
'run into small building' is the wordplay.
'run' becomes 'r' (cricket abbreviation).
'into' is an insertion indicator.
'small building' becomes 'hut' ().
'r' going inside 'hut' is 'HURT'.
(Other definitions for hurt that I've seen before include "John -, actor (The Elephant Man); harm" , "Ache" , "Injured" , "Cause pain to" , "Offend(ed)" .)