Transformation \Trans`for*ma"tion\, n. [L. transformatio: cf. transformation.]

The act of transforming, or the state of being transformed; change of form or condition. Specifically:
   (a) (Biol.) Any change in an organism which alters its general character and mode of life, as in the development of the germ into the embryo, the egg into the animal, the larva into the insect (metamorphosis), etc.; also, the change which the histological units of a tissue are prone to undergo. See Metamorphosis.

Source: Webster's Revised Unabridged Dictionary (1913)