What a twister is and what it does (4)
I believe the answer is:
wind
'it does' is the definition.
The definition suggests a singular noun which matches the answer.
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for wind that I've seen before include "Twist or turn (in course)" , "Air current; twist" , "Meander, breeze" , "trade, for example" , "Twist, turn; breeze" .)