Nabla Symbol

Nabla Symbol

Nabla is the symbol (∇). The name comes from the Greek word for a Hebrew harp, called the Nevel, which had a similar shape. Related words also exist in Aramaic and Hebrew. The symbol was first used by William Rowan Hamilton in the form of a sideways wedge: ⊲. Another, less-common name for the symbol is atled (delta spelled backwards), because the nabla is an inverted Greek letter delta. In actual Greek usage, the symbol is called ανάδελτα, anádelta, which means "upside-down delta".

The source of the name may come from the Persian word "del" دل (pronounced del and meaning 'heart') as the nabla shape is similar to the heart's shape in profile.

The nabla symbol is available in standard HTML as ∇ and in LaTeX as \nabla. In Unicode, it is the character at code point U+2207, or 8711 in decimal notation.