The term "learned the clarinet at school" is most commonly used by persons as a way of conveying the fact that they have been known to give fantastic oral sex, particularly on male genitalia.
"I learned the clarinet at school." John said, sending a wink in the direction of his room-mate.
A unicorn with a clarinet as a horn. one can be a clarineticorn by placing the bell of one's clarinet on their forehead and holding it there so that the rest of the clarinet sticks up like the horn of a unicorn. (usually done while running and/or making akward, loud noises)
Person 1: (running with their clarinet on their head) "AAAHH!!!"
Person 2: "dude, what's that guy doing"
Person 3: "oh he's just being a clarineticorn"
The phenomenon of playing a game on Steam and either getting killed or missing vital information due to Steam blocking out the bottom-right corner of the game to tell you that a friend has logged into a different game. Named for mailman Cliff Clavin from the TV show "Cheers," who often spouted useless, wrong, and/or unwanted trivia to the annoyance of the people around him.