monk
She decided to become a nun.
All the nuns live in this convent.

SMART Vocabulary: related words and phrases

Religious people: monks & nuns
abbess
abbey
abbot
anchorite
ascetic
benedictine
Franciscan
friar
friary
habit
hermit
lay brother
monastic
monastically
monasticism
monk
mother
priory
Trappist monk
veil

nun | American Dictionary

nun
noun[ C ]
us/nʌn/
a member of a female religious group whose members promise to obey the orders of the leader of the group, to be poor, and not to marry