Bass (the same word as "base," and so pronounced, but influenced in spelling by the Ital. basso), deep, low; especially in music, the lower part in the harmony of a composition, the lowest male voice, or the lowest-pitched of a class of instruments, as the bass-clarinet.

Bass or bast (a word of doubtful origin, pronounced băs) is the fibrous bark of the lime tree, used in gardening for tying up plants, or to make mats, soft plaited baskets, etc. Basswood is the American lime-tree, Tilia Americana; white basswood is T. heterophylla.

The name bass is also given to a fish closely resembling the perch.