the hole, slit, or loop through which a button is passed and by which it is secured.

Chiefly British . a boutonniere.

Surgery . a short, straight incision through the wall of a cavity or a canal.

to sew with a buttonhole stitch.

to make buttonholes in.

to hold by the buttonhole or otherwise abruptly detain (someone) in conversation

The reporter tried to buttonhole the mayor for a statement on the bus strike.

verb

accost , approach , detain , eyelet , loop , slip , stop