Bob does so if pushed! (6)
I believe the answer is:
swings
'bob does' is the definition.
The definition and answer can be both to do with motion as well as being verbs in their -s form.
Maybe you can see an association between them that I don't see?
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for swings that I've seen before include "Moves back and forth or from side to side while suspended" , "Pieces of playground equipment" , "Moves in a curve" , "Pieces of playground apparatus" , "Moves to and fro like pendulum" .)