divergence,
n. 1. (for a vector-valued function, A) the scalar quantity ∇. A or divA, defined in terms of the differential operator as
where i, j, k are unit vectors in the directions of the x-, y-, and z-axes respectively; if A=(u,v,w), then
Tijk... ei ⊗ ej ⊗ ek ⊗ ...
the quantity
∇.A = 
Compare gradient, curl.
2. more generally, for a Cartesian tensor
Tijk... ei ⊗ ej ⊗ ek ⊗ ...
the quantity