He’s mean (4)
I believe the answer is:
norm
This clue might be a double definition.
'he's' is the first definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'mean' is the second definition.
(I've seen this before)
Can you help me to learn more?
(Other definitions for norm that I've seen before include "expected thing" , "Average level of performance" , "Average level of achievement" , "Mean" , "Small boy" .)