An obelus (pl. "obeli") is a symbol consisting of a line with ots above and below, , used to represent the mathematical division operation. This symbol is also known as a division sign. The word "obelus" comes from the Greek word for a sharpened stick, spit, or pointed pillar. This is the same root as that of the word "obelisk". Originally this sign (or a plain line) was used in ancient manuscripts to mark passages which were suspected of being corrupted or spurious.