Is it ensure, insure, or assure?
derogatory word for "black person felt to have a 'white' mentality," 1968, black American English, from the snack cookies, which consist of dark chocolate wafers and white sugar cream filling (hence "brown outside, white inside"). The cookies (made by Nabisco) date from 1912; the source of the name has been forgotten.
A black person whose values, behavior, etc, are those of the white society; afro-saxon: I've been called a ''zebra'' and an ''Oreo''
[1960s+ Black; fr the trademark of a brand of sandwich cookies that have a white cream between round chocolate biscuits]