"pertaining to or characteristic of a religious recluse," mid-15c., monastik, from Old French monastique "monkish, monastic" and directly from Medieval Latin monasticus, from Ecclesiastical Greek monastikos "solitary, pertaining to a monk," from Greek monazein "to live alone" (see monastery). Related: Monastical (c. 1400).
word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.
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Harper, D. (n.d.). Etymology of monasticism. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/monasticism