Shelter invaded by old con (4,2)
I believe the answer is:
have on
'con' is the definition.
Although both the answer and definition are verbs in their base form, I don't understand how one could define the other.
'shelter invaded by old' is the wordplay.
'shelter' becomes 'haven' (haven is a kind of shelter).
'invaded by' indicates putting letters inside.
'old' becomes 'o' (abbreviation as in OT - Old Testament).
'haven' going around 'o' is 'HAVE ON'.
Can you help me to learn more?
(Other definitions for have on that I've seen before include "kid" , "Wear" , "Tease" .)