the inner nature of something which is responsible for its ultimate development and fulfillment. In Aristotelian philosophy, entelechy is seen as form, as distinguished from matter.
In Aristotelian philosophy, the principle of life, identified with the soul or psyche. The entelechy is both the formal or formative cause and the final cause, or end, of a living body; thus there is always an internalized purpose in life. In the vitalism (q.v.) of Hans Driesch, entelechy is the nonmaterial vital principle, a directive, teleological causal factor which brings about harmonious developmental, behavioural, and mental processes (cf. genetic program and morphic field).
Something having in it "a certain perfection", a completeness- a term taken from Aristotle's definition of the soul
The actualization of potentiality or of true existence in Aristotelian philosophy; vitalism -- the immanent force which controls and directs life and its development.
In Aristotle's use : The realization or complete expression of some function; the condition in which a potentiality has become an actuality'' ( The Oxford English Dictionary, Oxford University Press, London, 1933). “In Aristotle a : the full realization of form-giving cause or energeia as contrasted with mere potential existence b : the form that actuates this realization” ( Webster's Third New International Dictionary of the English Language, Unabridged, Merriam-Webster, Springfield, 1986 (orig. 1961). “ ‘Entelechy' is also a technical term in Leibniz for the primitive active force in every monad...” ( The Cambridge Dictionary of Philosophy, Cambridge University Press, Cambridge, 1995). “An inherent regulating and directing force in the development and functioning of an organism” ( Merriam-Webster's Collegiate Dictionary, Tenth Edition, Merriam-Webster, Springfield, 1996).
Entelechy is a philosophical concept of Aristotle. The term traces to the Ancient Greek word entelecheia, from the combination of the Greek words enteles (complete), telos (end, purpose, completion) and echein (to have). Aristotle coined the word, which could possibly be translated in English as, "having the end within itself."