noun

1. (derisive) One who is prone to butt in, interrupt, or get involved where they are not welcome.

   “I wish I had never met that nosy buttinsky!”

2. (usually buttinski) A robust portable one-piece telephone instrument with clips, used by technicians and lines staff for testing telephone circuits or making a temporary connection to a telephone line.

Synonyms: backseat driver, busybody, kibitzer, meddler