To vacate an area completely of all humans, usually rapidly and in response to an emergency situation.

etymology: "de-" (prefix, "remove") + "ass" = "get everyone's asses out of here"
When the bomb threat came, everyone was in a big hurry to deass the area.
by tora321 June 3, 2010
Get the Deass mug.
Deass: To exit or leave any given place.
I'm glad this shift is just about over, I'm ready to deass this place.
by vernon February 3, 2004
Get the Deass mug.