The phrase involves a physical action, usually crushing the cigarette's lit end against an ashtray or other surface.

Physical Action

'Stubbing out' implies an abrupt end, as if the smoker decides to stop smoking immediately.

Sudden Interruption

It conveys that the cigarette will no longer be used; it is the final action of a smoking session.

In computing, 'stubbing out' means creating a placeholder that doesn't have the full functionality yet.

It's a strategy used early in software development when full details or systems aren't ready.

'Stubbing out' simplifies testing by avoiding complex dependencies and focusing on functionality.