Weed round front of mayor's residence (4)
I believe the answer is:
home
'residence' is the definition.
(home is a kind of residence)
'weed round front of mayor's' is the wordplay.
'weed' becomes 'hoe' (I've seen this before).
'round' indicates putting letters inside.
'front of' suggests taking the first letters.
The first letter of 'mayors' is 'm'.
'hoe' going around 'm' is 'HOME'.
(Other definitions for home that I've seen before include "Place of origin" , "Residence" , "Habitual abode" , "chez nous?" , "In; institution" .)