look up any word, like kappa:
 
1.
Used to describe someone who thinks they've done a great deed, charitable action or sacrifice, but in reality they've done very little to help the human condition.
Earl: I gave that homeless man my half eaten apple.
Roger: Wow, thats mighty white of you.
by RjDudes August 23, 2006
 
2.
Originally used under colonialism and before civil rights, this phrase expressed appreciation for honorable or gracious behavior, under the assumption that white people were inherently more virtuous. Today, it is generally used sarcastically in reference to underwhelming acts of generosity.
In Jamaica in 1765:

A: I built the slaves a church to hang out in on Sundays, even though I didn't have to.
B: Well, that's mighty white of you.

In Harlem in 2010:

A: I'm feeling so generous, I'm gonna eat my food right next to you so you can enjoy the smell.
B: Well God damn, that's mighty white of you - How could I ever repay you for such a selfless act?
by Hollywood Cemetery March 14, 2010
 
3.
to behave or act in a manner stereotypically attributed to Caucasians
That was mighty white of you to help with the charity ball.
by Bertha M. Butts December 21, 2005
 
4.
Foolish phrase used by some to show so-called white superiority. Phrase attributed to the south, and coined during days of slavery. Now sometimes said in a sarcastic manner to people who act as they are superior because of their race.
When Bob threw a nickle into the UNICEF can at the office, and said "Those people should be glad I felt so generous." I said to him "That's mighty white of you ass."
by 524484452 June 02, 2008