The core of an apple that is left after the rest of it has been eaten.
This word was used in Northern Ireland and in Scotland in the 1940’s, ‘50’s and ‘6o’s, at least. I was someone who experienced its use then, in Belfast. Sometimes young children would ask of other children , or parents, if they could have the Butsy of the apple they were eating, so they could nibble on the remains.
When a song is so great that you just can control yourself so you 🅱️🅾️🅿️ your 🅱️USSY
Me: hand me the aux cord
Friend: you better not play any crap music Me: I got you. Your gonna {bop your bussy}
Me: *plays Tetris But Brendon Urie laughing*
CrankThatFrank in the background: IM BOPPING MY BUSSY RIGHT NOW