tune-up vs adjustment

tune-up and adjustment both are nouns.

Word	Noun	Adjective	Verb	Adverb
tune-up	Yes	No	No	No
adjustment	Yes	No	No	No

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

Other hypernyms of tune-up include readjustment, registration.

tune-up (noun)	adjustment (noun)
adjustments made to an engine to improve its performance	the act of making something different (as e.g. the size of a garment)
exercising in preparation for strenuous activity	the act of adjusting something to match a standard
	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)