adjustment vs betterment

adjustment and betterment both are nouns.

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

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

Other hypernyms of adjustment include advance, improvement.

adjustment (noun)	betterment (noun)
the act of making something different (as e.g. the size of a garment)	the act of relieving ills and changing for the better
the act of adjusting something to match a standard	a change for the better; progress in development
making or becoming suitable; adjusting to circumstances	an improvement that adds to the value of a property or facility
an amount added or deducted on the basis of qualifying circumstances
the process of adapting to something (such as environmental conditions)