What is "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.

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

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 is a genus of moth in the family Geometridae.