Do anything but help look after the little terror (6)
I believe the answer is:
impair
'do anything but help' is the definition.
I can't judge whether this defines the answer.
'look after the little terror' is the wordplay.
'look' becomes 'air' (something might have a certain air or look).
'after' means one lot of letters go next to another.
'the little terror' becomes 'imp' (mischievous spirit).
'air' after 'imp' is 'IMPAIR'.
Can you help me to learn more?
(Other definitions for impair that I've seen before include "Cause weakening of, damage" , "Hinder" , "Make worse or less effective" , "Spoil, degrade" , "Hurt or handicap" .)