Part-time medic and explorer land in Westminster (4,4)
I believe the answer is:
hyde park
'land in westminster' is the definition.
The definition suggests a singular noun which matches the answer.
'part-time medic and explorer' is the wordplay.
'part time medic' becomes 'hyde' (I can't explain this - if you can you should believe this answer much more).
'and' says to put letters next to each other.
'explorer' becomes 'park' (I have seen 'Scottish explorer' mean 'park' so perhaps 'explorer' could also mean 'park').
'hyde'+'park'='HYDE PARK'
Can you help me to learn more?
(Other definitions for hyde park that I've seen before include "Public open space in Central London" , "Marble Arch location" , "London green space" , "place of recreation" , "Open area in London" .)