·noun One of the elements; a metal of a reddish white color, crystallizing in rhombohedrons. It is somewhat harder than lead, and rather brittle; masses show broad cleavage surfaces when broken across. It melts at 507° Fahr., being easily fused in the flame of a candle. It is found in a native state, and as a constituent of some minerals. Specific gravity 9.8. Atomic weight 207.5. Symbol Bi.