The difference between metalaxia and metaplasia?

Metaplasia is a process where one type of cell is replaced by another type, often due to tissue damage or inflammation
Metallaxis is "an obsolete term that dignified any alteration of an organ or tissue by a pathologic process; pathological healing of organ damage." [1]
Metalaxia is described by some sources as an organism's ability to adapt to changing environments.

Sources:
[1] https://medical-dictionary.thefreedictionary.com/metallaxis