To accost or detain a person in order to force them to engage you in conversation.
Man, I dropped by this party last night to say hey to a friend, and my ex was there, and before I could get out she totally buttonholed me in the foyer and starting crying about how we should get back together. It was messy.
Her skirt is so short and she wears no panties. You can almost see her buttonhole.
The thing Annie Lennox whistles through as she bounces home crying
I don't find my self bouncing home whistling buttonhole tunes to make me cry
May sometimes be confused for a Whistling Bunghole