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.
(..) No, Miss Prescott, you mustn't say that. Yes. D for down. D for dreary. D for dull and for depressing, dismal and deadly! Ahh! Here it is. Here is our theme. Here is our answer. Pink. Girls, girls, girls, girls. Take this to all the designers. (..)1957 Funny Face