It’s equatable to a miss (4)
I believe the answer is:
mile
'a miss' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'it's equatable' 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.
The remaining letters 'mil' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for mile that I've seen before include "Imperial length" , "Unit of distance" , "Measure" , "Unit of length" , "1.61km" .)