Dwell to the north, welcoming fix for part of entrance (8)
I believe the answer is:
doorjamb
'entrance' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'dwell to the north welcoming fix for part' is the wordplay.
'dwell' becomes 'brood' (synonyms).
'to the north' is a reversal indicator (in a down clue, letters go up or 'north').
'welcoming' is an insertion indicator (in sense of 'inviting in').
'fix for part' becomes 'jam' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'brood' back-to-front is 'doorb'.
'doorb' going around 'jam' is 'DOORJAMB'.
'of' is the link.
Can you help me to learn more?
(Other definitions for doorjamb that I've seen before include "Side post at entrance" , "Entranceway post" , "Post beside entrance" , "Entrance sidepost" , "Vertical post by entrance" .)