##### The Collaborative International Dictionary

**nabla**

del \del\ n. (Math.) a differential operator which, operating on a function of several variables, gives the sum of the partial derivatives of the function with respect to the three orthogonal spatial coordinates; -- also called the gradient or grad. It is represented by an inverted Greek capital delta ([nabla]), and is thus because of its shape also called nabla, meaning harp in Hebrew.

##### Wiktionary

**nabla**

n. 1 (Hebrew) A Hebrew stringed instrument. 2 (context analysis English) The symbol ∇, used to denote the gradient operator.

##### Wikipedia

**Nabla**

**Nabla** may refer to one of the following:

- the nabla symbol ∇
- the vector differential operator, also called del, denoted by the nabla
- Nabla, tradename of a type of rail fastening system (of roughly triangular shape)
- Nabla (moth), a genus of moth
- Nabla (instrument), the Greek word for a Phoenician or Hebrew stringed instrument after the triangular shape of which all of the above are named

**Nabla (moth)**

** Nabla** is a genus of moth in the family Geometridae.

#### Usage examples of "nabla".

The `dot product' and the `cross product' after the __nablas__ are statements of two different kinds of spatial variation.

The 'dot product' and the 'cross product' after the __nablas__ are statements of two different kinds of spatial variation.