Hawt = A late 1940's and early 1950's acronym for "Having A Wonderful Time."
Now the word is used on the internet as slang for something reeeeally hot.
After putting 26 year old Jason Wu firmly on the fashion map at the 2009, Michelle Obama once again turned to the same designer to create her striking red, velvet and chiffon gown, at last weekend’s Inaugural Ball. The sleeveless dress highlighted Michelle’s famously toned arms, and she accessorized with Jimmy Choo high heels. The First Lady looked HAWT. Everyone wolfwhistle: Twit-Wu!