adaptation vs adaption

adaptation and adaption both are nouns.

Word	Noun	Adjective	Verb	Adverb
adaptation	Yes	No	No	No
adaption	Yes	No	No	No

As nouns, adaptation and adaption are synonyms defined as:

adaptation and adaption: the process of adapting to something (such as environmental conditions)

Other synonyms of adaptation include adjustment.

adaptation (noun)	adaption (noun)
(physiology) the responsive adjustment of a sense organ (as the eye) to varying conditions (as of light)	the process of adapting to something (such as environmental conditions)
a written work (as a novel) that has been recast in a new form
the process of adapting to something (such as environmental conditions)