nomadism vs modus vivendi

nomadism and modus vivendi both are nouns.

Word	Noun	Adjective	Verb	Adverb
nomadism	Yes	No	No	No
modus vivendi	Yes	No	No	No

As nouns, modus vivendi is a hypernym of nomadism; that is, modus vivendi is a word with a broader meaning than nomadism:

nomadism: The way of life of people who, having no fixed home, move around seasonally in search of food, water and grazing etc.
modus vivendi: a manner of living that reflects the person's values and attitudes

Other hypernyms of nomadism include life-style, life style, lifestyle.

nomadism (noun)	modus vivendi (noun)
The way of life of people who, having no fixed home, move around seasonally in search of food, water and grazing etc.	a manner of living that reflects the person's values and attitudes
	a temporary accommodation of a disagreement between parties pending a permanent settlement