Del
Del , noun
[See Deal, n.]
Share; portion; part. [Obsolete] — Chaucer
del , noun
(Mathematics) 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 (n), and is thus because of its shape also called nabla, meaning harp in Hebrew.