First World Twat 

A person who genuinely and seriously calls out somebody's legitimate complaint as a first world problem as a means of trivialising them and their complaint, usually to obtain a smug sense of moral superiority because of how 'in touch' they are with the 'plight of the underprivileged'.

Dave: "Great, my air conditioner just died in the middle of a heatwave! This sucks."

Twat: "This is such a first world problem. At least you have a house and clothes, and perpetual access to the internet on your smartphone to make these status updates."

Dave: "Don't be such a first world twat."

First World Twat by Cult Kitten January 17, 2014