A person who is absolutely obsessed with Paul McCartney including his Beatle, Wings, Fireman and solo career. They can give you a speech on his life and can name every single album and single ever released by him. They might break down and cry at any moment just by the thought or sight of his beautiful face. The term Macca refers to Paul's nickname deriving from the first 2 syllables of his last name. They are awesome people and have flawless taste in music. Buying them Paul McCartney merch/tickets is like buying pure gold.
Bob- who's that girl with the Paul McCartney shirt on? She seems cool.
Jim- oh that's Maggie. She's obsessed with Paul McCartney and also with the Beatles.
Bob- oh so she's a Beatlemaniac?
Jim- yea she's also a complete Maccamaniac. She's so cool.