Father goes back and forth, chased by pest on alternate quest for machinery (9)
I believe the answer is:
apparatus
'for machinery' is the definition.
(I've seen this before)
'father goes back and forth chased by pest on alternate quest' is the wordplay.
I cannot quite see how this works, but
'father' could be 'pa' (pa can mean dad or father) and 'pa' is found within the answer.
'by' could be 'at' and 'at' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for apparatus that I've seen before include "Piece of equipment" , "Equipment, gear" , "Technical equipment" , "Equipment designed for a specific function" , "system" .)