Loose Cannon
Noun · Slang & Abbreviations
Definitions
A person, tool, or process that is unpredictable enough to create risk for everyone nearby. In engineering slang, loose cannons may be effective sometimes, but nobody wants to be within their blast radius during a release.
In plain English: Someone or something powerful but unpredictable and risky.
Example: "He was a brilliant debugger but a loose cannon in review, landing broad refactors without enough warning for teams that depended on those interfaces."