Del /(?)/

Del

n.
  1. Share; portion; part. [Obs.]

del

n.
  1. 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 (∇), and is thus because of its shape also called nabla, meaning harp in Hebrew. (Math.)