conversation ninja 

A third party who "ninjas" their way into a conversation they were not originally a part, usually with a comment which mean they have been eavesdropping for an extended period of time, like a ninja striking in the shadows.

Jackie just pulled a conversation ninja. I didn't even notice her before she dropped that comment about her Lexus while we were talking about luxury cars.

conversation ninja by rmsiii December 11, 2007

Conversation Ninja 

One makes a single random comment in someone elses conversation, which ends up killing it and making it awkward for everyone else. This is similar to a ninja swiftly killing a target then exiting.

Guy 1: Hey, do you see that really hot chick over there?
Guy 2: Hell yea, Id hit that all night!
Conversation Ninja: I screwed her and gave her herpes *disappears*
Guy 1: Oh... Im gonna go now.

Conversation Ninja by ThruTheDesertOvrTheFence September 13, 2009

ninja conversation 

A conversation dominated by verbal grappling hooks and sharpened metaphors that sneak soundlessly into the cracks of the mind. Common side effects include cloudiness, confusion and a general disdain for pirates.

That girl strikes the depths of my cranium with deft hands and my heart with a fingertip touch that seeps down to the very edges of my shadow. (General response to this "ninja conversation" follows with trailing off, averting eyes and mumbling about eye patches and single consonant words)

ninja conversation by vernacular_ninja September 24, 2009