# subderivative

## EnglishEdit

### EtymologyEdit

*sub-* + *derivative*

### NounEdit

**subderivative** (*plural* **subderivatives**)

- (linguistics) A word derived indirectly, from a derivative of another.
*"Friendliness" is a***subderivative**: it is derived from "friendly", which comes from "friend".

- (mathematics) A generalization of the notion of a derivative, defined as the slope of a line that either touches, or is everywhere below the line of a convex function.