Racism oddly ignored in mission (3)
I believe the answer is:
aim
'mission' is the definition.
(I've seen this before)
'racism oddly ignored' is the wordplay.
'oddly ignored' means one should take alternating letters (letters in odd-numbered positions are removed).
The alternate letters of 'racism' are 'AIM'.
'in' acts as a link.
(Other definitions for aim that I've seen before include "Direct, intend" , "Plan" , "Set sights on, target or goal" , "Steady, ... fire" , "intent" .)