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.
You know it’s been a good day when the only person to upstage your amazing dress is… well, yourself, merely a few hours later! Not only did Best Supporting actress Alicia Vikander win the biggest red carpet high five of the day in her dusty yellow Louis Vuitton gown, but later that night at the Vanity Fair party, the beauty’s sequinned, black Louis Vuitton dress saw no real competition. Congratulations Alicia!
