Back up (7)
'back up' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for reverse that I've seen before include "Change" , "Drive backwards" , "One side of a coin" , "Travel backwards" , "Tails (of a coin)" .)
'back up' is the definition.
(assisting is a kind of backing up)
This is the entire clue.
(Other definitions for assist that I've seen before include "Help, lend a hand" , "Expedite" , "Understand by instinct" , "Give aid" , "provide backing" .)