adaptation vs adjustment

adaptation and adjustment both are nouns.

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

As nouns, adjustment is a hypernym of adaptation; that is, adjustment is a word with a broader meaning than adaptation:

adaptation: (physiology) the responsive adjustment of a sense organ (as the eye) to varying conditions (as of light)
adjustment: the act of making something different (as e.g. the size of a garment)

Other hypernyms of adaptation include alteration, modification.

As nouns, adaptation and adjustment are synonyms defined as:

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

Other synonyms of adaptation include adaption.

adaptation (noun)	adjustment (noun)
(physiology) the responsive adjustment of a sense organ (as the eye) to varying conditions (as of light)	the act of making something different (as e.g. the size of a garment)
a written work (as a novel) that has been recast in a new form	the act of adjusting something to match a standard
the process of adapting to something (such as environmental conditions)	making or becoming suitable; adjusting to circumstances
	an amount added or deducted on the basis of qualifying circumstances
	the process of adapting to something (such as environmental conditions)