Every second of racism is mean (3)
I believe the answer is:
aim
'is mean' is the definition.
(I've seen this in another clue)
'every second of racism' is the wordplay.
'every second of' indicates alternate letters.
The alternate letters of 'racism' are 'AIM'.
(Other definitions for aim that I've seen before include "This is mean" , "anticipated" , "mission" , "Point (gun); intention" , "Try to achieve" .)