an orgasm induced by witnessing or hearing something of or related to theatre, or the act of having a theatregasm. Often used figuratively.
TED: "Hey, John, the musical Mary Poppins is coming to town!"
JOHN: "Oh my goodness, I'm so excited I just had a theatregasm!"
SARAH: "Hey, Sierra, listen to Connor sing this really amazing bass note."
CONNOR: *sings amazing bass note*
SIERRA: "Gah! I just theatregasmed!"