monastical vs monastic

monastical is not a noun while monastic is a noun.

Word	Noun	Adjective	Verb	Adverb
monastical	No	Yes	No	No
monastic	Yes	Yes	No	No

As adjectives, monastical and monastic are synonyms defined as:

monastical and monastic: of communal life sequestered from the world under religious vows

Other synonyms of monastical include cloistered, cloistral, conventual.

monastical (noun)	monastic (noun)
	a male religious living in a cloister and devoting himself to contemplation and prayer and work

monastical (adjective)	monastic (adjective)
of communal life sequestered from the world under religious vows	of communal life sequestered from the world under religious vows