Botanical garden a nuisance, corporation bringing in bulldozer finally (9)
I believe the answer is:
arboretum
'botanical garden' is the definition.
(synonyms)
'a nuisance corporation bringing in bulldozer finally' is the wordplay.
'nuisance' becomes 'bore' (I've seen this before).
'corporation' becomes 'tum' ('corporation' is a humorous term for stomach fat).
'bringing in' means one lot of letters goes inside another.
'finally' suggests the final letters.
The final letter of 'bulldozer' is 'r'.
'a'+'bore'+'tum'='aboretum'
'aboretum' enclosing 'r' is 'ARBORETUM'.
(Other definitions for arboretum that I've seen before include "Tree display centre" , "Where planes may be" , "there's high growth" , "Place for cultivation of 19s" , "Collection of elders, say" .)