What is the meaning of Buttonhole?

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

A flower worn in a buttonhole for decoration.

So shaped that it can be worn on a buttonhole or it is similar to a buttonhole.

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.

vagina, coin slot.

butthole: anus.

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

To cut one or more buttonholes (in).

To sew by buttonhole stitch.

To make a small slot-like incision in (intentionally or unintentionally).

To apply a flowery formation in.

To attain buttonhole-like formations on cutting.

Source: wiktionary.org