Coach tackling queen to the ground (7)
I believe the answer is:
terrain
'the ground' is the definition.
(terrain is land or ground)
'coach tackling queen' is the wordplay.
'coach' becomes 'train' (both can mean to instruct a sportsperson).
'tackling' is an insertion indicator (to tackle is to take possession of).
'queen' becomes 'ER' (short for Elizabeth Regina ie Queen Elizabeth).
'train' going around 'er' is 'TERRAIN'.
'to' is the link.
(Other definitions for terrain that I've seen before include "Physical feature of a stretch of ground" , "Land (as base for action)" , "Land with respect to its features" , "Tract of land with particular character" , "Area of ground with a particular characteristic" .)