- Partly burned or vitrified coal, or other combustible, in which fire is extinct.
- A hot coal without flame; an ember.
- A scale thrown off in forging metal.
- The slag of a furnace, or scoriaceous lava from a volcano.
Etymology: AS. sinder slag, dross; akin to Icel. sindr dross, Sw. sinder, G. sinter, D. sintel; perh. influenced by F. cendre ashes, fr. L. cinis. Cf. Sinter