Binder

A piece of clothing that beares some resemblance to a sports bra, that constricts and flattens the chest. Mostly, though not always, worn by transgender men. (Other examples include: non-binary folks, women who want a more androgynous look, and some others.)

I bought a new binder yesterday, my current one is getting very old.

I just ordered a binder, I can't wait to look more androgynous!