Origin

This character combines a picture of a cave or enclosed space (the top part, which looks like a hole) with a sound hint at the bottom that tells you roughly how to pronounce it. The cave or hidden space naturally connects to the idea of secrecy and stealth — things that happen out of sight, in the shadows. When something is stolen or done in secret, it happens away from view, just like something hidden inside a cave or enclosed space. Over time, the character came to mean stealth, stealing, and anything secretive or private.