derivation

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The act or process of deriving.
• noun The state or fact of being derived; origination.
• noun Something derived; a derivative.
• noun The form or source from which something is derived; an origin.
• noun The historical origin and development of a word; an etymology.
• noun The process by which words are formed from existing words or bases by adding affixes, as singer from sing or undo from do, by changing the shape of the word or base, as song from sing, or by adding an affix and changing the pronunciation of the word or base, as electricity from electric.
• noun In generative linguistics, the generation of a linguistic structure through an ordered or partially ordered series of operations on other structures, such as the creation of a surface structure from a deep structure, or of a complex word from its morphological components.
• noun The formal description of the process of such generation.
• noun Logic & Mathematics A logical or mathematical process indicating through a sequence of statements that a result such as a theorem or a formula necessarily follows from the initial assumptions.

from The Century Dictionary.

• noun A drawing from or turning aside, as a stream of water or other fluid from a natural course or channel; a stream so diverted.
• noun Specifically
• noun The act or fact of deriving, drawing, or receiving from a source: as, the derivation of being; the derivation of an estate from ancestors, or of profits from capital.
• noun In philology, the drawing or tracing of a word in its development or formation from its more original root or stem; a statement of the origin or formative history of a word. See etymology.
• noun In mathematics: The operation of finding the derivative, or differential coefficient; differentiation.
• noun The operation of passing from any point on a cubic curve to that point at which the tangent at the first point cuts the curve.
• noun The operation of passing from any function to any related function which may in the context be termed its derivative. The word derivation, in its first mathematical sense, was invented by Lagrange, who thought it possible to develop the calculus without the use of infinitesimals.
• noun In biology, descent with modification of an organism from antecedent organisms; evolution: as, the derivation of man; the doctrine of derivation—that is, the derivative theory (which see, under derivative).
• noun In gunnery, the peculiar constant deviation of an elongated projectile from a rifled gun, due to its angular rotation about its longer axis and to the resistance of the air. Sometimes called drift.
• noun The thing derived or deduced; a derivative; a deduction.

from the GNU version of the Collaborative International Dictionary of English.

• noun obsolete A leading or drawing off of water from a stream or source.
• noun The act of receiving anything from a source; the act of procuring an effect from a cause, means, or condition, as profits from capital, conclusions or opinions from evidence.
• noun The act of tracing origin or descent, as in grammar or genealogy.
• noun The state or method of being derived; the relation of origin when established or asserted.
• noun That from which a thing is derived.
• noun That which is derived; a derivative; a deduction.
• noun (Math.) The operation of deducing one function from another according to some fixed law, called the law of derivation, as the operation of differentiation or of integration.
• noun (Med.) A drawing of humors or fluids from one part of the body to another, to relieve or lessen a morbid process.
• noun The formation of a word from its more original or radical elements; also, a statement of the origin and history of a word.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A leading or drawing off of water from a stream or source.
• noun The act of receiving anything from a source; the act of procuring an effect from a cause, means, or condition, as profits from capital, conclusions or opinions from evidence.
• noun The act of tracing origin or descent, as in grammar or genealogy; as, the derivation of a word from an Indo-European root.
• noun The state or method of being derived; the relation of origin when established or asserted.
• noun That from which a thing is derived.
• noun That which is derived; a derivative; a deduction.
• noun mathematics The operation of deducing one function from another according to some fixed law, called the law of derivation, as the of differentiation or of integration.
• noun medicine A drawing of humors or fluids from one part of the body to another, to relieve or lessen a morbid process.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the source or origin from which something derives (i.e. comes or issues)
• noun inherited properties shared with others of your bloodline
• noun (historical linguistics) an explanation of the historical origins of a word or phrase
• noun (descriptive linguistics) the process whereby new words are formed from existing words or bases by affixation
• noun drawing off water from its main channel as for irrigation
• noun a line of reasoning that shows how a conclusion follows logically from accepted propositions
• noun drawing of fluid or inflammation away from a diseased part of the body
• noun the act of deriving something or obtaining something from a source or origin