Definition & Meaning of "off the radar"in English

What does "off the radar" mean in slang?

The structure uses "radar" as a metaphor for detection or attention, forming a phrase that describes something hidden or unnoticed. It is used to describe someone or something that is not being tracked, monitored, or considered, often deliberately avoiding attention. People typically say a person is "off the radar" when they have gone quiet or disappeared from public view, or that an issue is "off the radar" when no one is paying attention to it. The term originated in mid 20th century military and aviation jargon, later spreading into general use as the opposite of "on one's radar."