Rotary motor (7)
I believe the answer is:
'rotary motor' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for turbine that I've seen before include "Type of engine with internal bladed rotor" , "Power generator" , "Machine producing power when water drives a rotor, for example" , "Rotary engine" , "Power-producing machine" .)