to purposely ignore a comment made by someone based solely on the fact that they are black

Stupid shit that "Niggas" do. Not black people, (the productive ones), but "Niggas".

when somebody does something that supports a negative stereotype of black people

An ignorant nigga...someone (anyone, not limited to those of African American descent) who perpetuates and overexeplifies the stereotypical behavior known to being a nigga. Such as being loud in public, doing wraunchy dances in public, extra flamboyant hair colors, cussing at kids in church, sleeping after all meals, cussing out regular people cuz they left out the extra hot sauce you ordered with your super sized box of chicken wings, stealin cable and getting your telephone line cut back on in your childs name, and the list could go on forever and ever, Amen.

When someone is being both real niggerish and ingnorant at the same time

When a black person acts obnoxious or ignorant, often in fits of joy, rage, or complete randomness. Physical signs of Nignorance include excessive yelling, gross movements of appendages, and jumping.

When some does or says something that only a nigger would do.