(medicine, cardiology, sometimes attributive) A kind of prosthetic heart valve characterized by two semicircular leaflets.

(physics) Any of several devices that permit apodization of an optical or electrical signal

(by extension) To utter a murmuring sound; to speak with a low, humming voice. / Of a group of people, to talk about some interesting topic excitedly.

A tablet or register. / (by extension) A list or scheme inscribed on a tablet.