it is when some one crouches down breathes heavily for a period of time(until feeling light headed), and then taking a hit of marijuana while slowly standing up. I have passed out numerous times doing this and a few friends ahve passed out too. The longer you hold your hit in the more likey you will pass out.
"Yo dude i took an elevator hit today, and i passed out and hit the ground man!"
when you're smoking weed and after inhalation, before you suck in the extra air, stand up and tilt your head all the way up and suck in the air.
duuuude i was with my buds by the river..we did elevator hits out of a coke can..fucked us UP!