Best definition
An ecstasy experienced when your writing is going particularly well (a scene comes out exactly as you pictured it in

your head; you’re in the shower and you suddenly get unstuck on a story; your writing is so good and flows so easily it’s like the muse has your hand; your writer’s block ends; etc).

I totally had a writergasm yesterday: a scene came to me and I was able to write it word for word exactly as it was in my head.