Dominicus vs day of rest

Dominicus and day of rest both are nouns.

Word	Noun	Adjective	Verb	Adverb
Dominicus	Yes	No	No	No
day of rest	Yes	No	No	No

As nouns, day of rest is a hypernym of Dominicus; that is, day of rest is a word with a broader meaning than Dominicus:

Dominicus: first day of the week; observed as a day of rest and worship by most Christians
day of rest: a day set aside for rest

Other hypernyms of Dominicus include rest day.

Dominicus (noun)	day of rest (noun)
first day of the week; observed as a day of rest and worship by most Christians	a day set aside for rest