Edgy Instagram duo cause harm (6)
I believe the answer is:
impair
'harm' is the definition.
(I've seen this in another clue)
'edgy instagram duo cause' is the wordplay.
I cannot really see how this works, but
'duo' could be 'pair' (synonyms) and 'pair' is found in the answer.
The remaining letters 'im' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for impair that I've seen before include "Damage or handicap" , "Harm" , "Hurt or handicap" , "Make worse or less effective" , "Hobble" .)