A hole through which a button is pushed to secure a garment or some part of one.

(chiefly Britain) A flower worn for decoration in a buttonhole or something shaped like a buttonhole.

(surgery) A small slot-like cut or incision, made for example by an accident with the scalpel.

The mouth and/or nose and/or eyes if appearing tiny.

(lightly vulgar) anus, batty hole.

(transitive, colloquial) To detain (a person) in conversation against their will.

(transitive, intransitive) To cut one or more buttonholes (in).

(transitive) To sew by buttonhole stitch.

(transitive, rare) To apply a flowery formation in.