To confine or accost someone in or with conversation. Likened to holding onto someone by the lapels (on which the buttonhole used for a boutonniere is located). I tried to leave the office early, but Larry buttonholed me with a tedious conversation about weekend plans.
See also: buttonhole
tv. to accost someone; to make someone listen to one. (As if grabbing someone by the coat lapel to keep them from getting away.) The guy buttonholed me on my way out, and started asking me a lot of questions.