in botany, a genus of mosses belonging to the cryptogamia algae. The character is taken from this circumstance, that they are covered with a simple capillary filament or down, resembling soft dust. The species are 15, all natives of Britain.

in antiquity, that fine Egyptian linen whereof the tunics of the Jewish priests were made.

Philo says, that the byssus is the clearest and most beautiful, the whitest, strongest, and most glossy sort of linen; that it is not made of anything mortal, that is to say, of wool, or the skin of any animal, but that it comes out of the earth, and becomes always whiter, and more shining, when it is washed as it should be.