Noun - A state of being under the influence of one's favorite drug. Taken from the Nirvana song 'Sappy' which has a chorus of "You're in a laundry room" over and over. Despite the song's meaning having nothing to do with the slang definition, the term was coined under the influence of a good deal of acid.
"Yo, you trippin' man?"
"Yeah, I'm in a laundry room"
"Hey, where's Jeff the junkie?"
"Don't even bother, he's in a laundry room right now."