Wordnet 3.0
ADJECTIVE (2)
1. 
 of or related to genetically distinguished groups of people; 
- Example: "racial groups"2. 
 of or characteristic of race or races or arising from differences among groups; 
- Example: "racial differences"- Example: "racial discrimination"
The Collaborative International Dictionary of English v.0.48:
Racial \Ra"cial\ (r[=a]"shal), a.
   Of or pertaining to a race or family of men; as, the racial
   complexion.
   [1913 Webster]
WordNet (r) 3.0 (2006):
racial
    adj 1: of or related to genetically distinguished groups of
           people; "racial groups"
    2: of or characteristic of race or races or arising from
       differences among groups; "racial differences"; "racial
       discrimination" [ant: nonracial]