When using one in a game, the Call of Duty slang term "Dead Silence" is used to describe being quiet and unnoticeable.
Person 1: "Yo bro where the last guy at I can't hear him at all"
Person 2: "I think he just popped a deady so just try to your best to clutch it
Person 1: "Man you're no help"
'Deady Dyckman' is a term that originated in Manhattan, New York City, and is used to express emphasis on something. The first use of the word came from the Acapulco Deli on Dyckman Street.
Lenny Acapulco invented the term by notoriously saying in 2002 "We outside this summer, its on DEADY DYCKMAN YURR"
"Wtm broski" said hoodfavv.$id
"We should goget food on deady dyckman" said EBK T2