An expression used mostly by fans of British rock band The Who as a reference to an astounding, mind-boggling, wonderful event. The term comes The Who's bassist John Entwistle, widely agreed to be the greatest bass player of all time.
by JackJones April 20, 2008
The result of listening to the astoundingly brilliant bass playing of a one Mr. John Entwistle of The Who.
I listened to the bass track on Won't Get Fooled Again last night and automatically had an Entwistlegasm
by Fool_1_2_3 April 20, 2008