Definition of monasterial in US English:
monasterial
adjective
Belonging to or of the nature of a monastery.
Origin
Late Middle English; earliest use found in Reginald Pecock (c1392–?1459), bishop of Chichester and religious author. From post-classical Latin monasterialis from monasterium + -alis.
Pronunciation
monasterial
/ˌmɒnəˈstɪərɪəl/