missal vs prayerbook

missal and prayerbook both are nouns.

Word	Noun	Adjective	Verb	Adverb
missal	Yes	No	No	No
prayerbook	Yes	No	No	No

As nouns, prayerbook is a hypernym of missal; that is, prayerbook is a word with a broader meaning than missal:

missal: (Roman Catholic Church) a book containing all the prayers and responses needed to celebrate Mass throughout the year
prayerbook: a book containing prayers

Other hypernyms of missal include prayer book.

missal (noun)	prayerbook (noun)
(Roman Catholic Church) a book containing all the prayers and responses needed to celebrate Mass throughout the year	a book containing prayers