Divergence

noun

1. The degree to which two or more things diverge.

   "An angle is made by the divergence of straight lines."

2. The operator which maps a function F=(F1, ... Fn) from a n-dimensional vector space to itself to the number \sum_{i=1}^n \frac{\partial F_i}{\partial x_i}
3. Disagreement; difference
4. The process in which two or more populations accumulate genetic changes (mutations) through time.