Possible Definitions:
1. Derivative (a.) Obtained by derivation; derived; not radical, original, or fundamental; originating, deduced, or formed from something else; secondary; as, a derivative conveyance; a derivative word.
2. Derivative (n.) That which is derived; anything obtained or deduced from another.
3. Derivative (n.) A word formed from another word, by a prefix or suffix, an internal modification, or some other change; a word which takes its origin from a root.
4. Derivative (n.) A chord, not fundamental, but obtained from another by inversion; or, vice versa, a ground tone or root implied in its harmonics in an actual chord.
5. Derivative (n.) An agent which is adapted to produce a derivation (in the medical sense).
6. Derivative (n.) A derived function; a function obtained from a given function by a certain algebraic process.
7. Derivative (n.) A substance so related to another substance by modification or partial substitution as to be regarded as derived from it; thus, the amido compounds are derivatives of ammonia, and the hydrocarbons are derivatives of methane, benzene, etc.