If it was eradicated there'd be no complaints (7)
I believe the answer is:
illness
'if' is the definition.
I can't judge whether this definition defines the answer.
'it was eradicated there'd be no complaints' is the wordplay.
I cannot really understand how this works, but
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is present in the answer.
'no' could be 'n' (common abbreviation y/n) and 'n' is found in the answer.
'complaints' could be 'ills' ('ill' can be a synonym of 'complaint') and 'ills' is found in the remaining letters.
A single letter 's' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for illness that I've seen before include "Indisposition, sickness" , "Ailment, disorder" , "Disease, sickness" , "Sick condition" , "Malady, sickness" .)