Understands the woman's after gun (7)
I believe the answer is:
gathers
'understands' is the definition.
('gather' can be a synonym of 'understand')
'woman's after gun' is the wordplay.
'woman's' becomes 'hers' (her refers to a woman).
'after' says to put letters next to each other.
'gun' becomes 'gat' (US informal term for a gun).
'hers' after 'gat' is 'GATHERS'.
'the' is the link.
(Other definitions for gathers that I've seen before include "Harvests" , "Assembles" , "Collects in one place" , "Understands" , "Gleans" .)