One section of large house or section of window in greenhouse (4)
I believe the answer is:
wing
'one section' is the definition.
(thesaurus)
'of window in greenhouse' is the wordplay.
'of' indicates the answer is hidden within the clue.
'WING' is hidden within 'window in greenhouse'.
'of large house or section' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for wing that I've seen before include "Aircraft's support" , "Arm adapted for flight" , "Stage area out of sight of the audience" , "Part of flier" , "Group of squadrons; par of car" .)