Type of conifer company cleared out on one of the estates (7)
I believe the answer is:
cypress
'type of conifer' is the definition.
(I know that cypress is a type of conifers)
'company cleared out on one of the estates' is the wordplay.
'cleared out' suggests removing the centre.
'on' means one lot of letters go next to another.
'one of the estates' becomes 'press' ('the fourth estate' can refer to the press).
'company' with its middle removed is 'cy'.
'cy'+'press'='CYPRESS'
(Other definitions for cypress that I've seen before include "symbol of death" , "Dark-leaved conifer" , "Coniferous tree" , "one rooted in the Med?" , "Wood" .)