divergence

Short definition from Wiktionary

Noun

1. 1
   The state or degree of being divergent: of diverging.
2. 2
   The operator which maps a function F=(F₁, ... Fₙ) from a n-dimensional vector space to itself to the function ∑ᵢ₌₁ⁿ(∂F_i)/(∂x_i).
3. 3
   Disagreement; difference.
4. 4
   The process in which two or more populations accumulate genetic changes (mutations) through time.