Regeneration (-shn), n.
Etymology: [L. regeneratio: cf. F. régéneration.]
1. The act of regenerating, or the state of being regenerated.
2. (Theol.)
The entering into a new spiritual life; the act of becoming, or of being made, Christian; that change by which holy affectations and purposes are substituted for the opposite motives in the heart. He saved us by the washing of regeneration, and renewing of the Holy Chost. Tit. iii. 5.
3. (Biol.)
2 more senses
The reproduction of a part which has been removed or destroyed; re-formation; -- a process especially characteristic of a many of the lower animals; as, the regeneration of lost feelers, limbs, and claws by spiders and crabs.
4. (Physiol.) (a) The reproduction or renewal of tissues, cells, etc., which have been used up and destroyed by the ordinary processes of life; as, the continual regeneration of the epithelial cells of the body, or the regeneration of the contractile substance of muscle. (b) The union of parts which have been severed, so that they become anatomically perfect; as, the regeneration of a nerve.
Shades of meaning
Fernald has no entry of its own for regeneration; he lists it under change.
Where he writes about it:
For the distinctions between the other words compare the synonyms for change, v. In the religious sense regeneration is the vital renewing of the soul by the power of the divine Spirit; conversion is the conscious and manifest change from evil to good, or from a lower to a higher spiritual state; as, in Luke xxii, 32, "when thou art converted, strengthen thy brethren." In popular use conversion is the most common word to express the idea of regeneration. — from change