<act, action, metaphysics, Aristotle, matter, Aquinas>, <Scholasticism, reality> (Gr. energeia / dynamis) Aristotle's distinction between what really is the case and what merely has the power to change or come to be the case. Thus, for example, this fresh acorn is actually a seed but only potentially an oak tree.
[A Dictionary of Philosophical Terms and Names]
Try this search on OneLook / Google