He's 'deadly' [='dead'] serious about finding another job.
Officers are allowed to use 'deadly force' if necessary.
The two gang leaders are 'deadly' enemies.
(..) Um... it could let in a draft? It could let in a child! Oh! Mr Waternoose! There is nothing more toxic or deadly than a human child. A single touch could kill you! Leave a door open and a child could walk right into this factory! Right into the monster world! (..)2001 Monsters, Inc.