Null unit

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Null unit is a profanity used by programs in the computer world. While its exact meaning is unknown, it most likely means "idiot" or "imbecile". Null is an English word meaning 'nothing' or without value, and in computing terms, "null" usually referrers to something indicating "no value" or an "unknown value".

Sark called his Lieutenant a "null unit" after Tron, Flynn, and Ram escaped from the Game Grid.

“	We better [get them], null unit!	”
—Sark