There really is no such thing, but the closest you can get is a monk.
The male counterpart of a nun is a monk.
NUN
Yes a "Monk" is the male equivalent of a "Nun".
The male equivalent of a nun is a monk, or a priest. However if you mean the opposite of an nun spiritually, that would be an atheist.
Adam Nun's birth name is Adam Joseph Nun.
The opposite gender of a monk (male) would be a nun (female).Nun
There is no such thing as a male nun. The male equivalent of a nun would be a monk. However, a monk may be ordained into the priesthood while a nun cannot be ordained. The male equivalent of a sister would be a brother, a member of a religious congregation for men who are not ordained.
A nun is a female member of a religious community who has taken vows of poverty, chastity, and obedience.
A convent or a nunnery is a housing quarters for a nun.
In most cases, a nun will choose her own new name when she enters the religious order. This name is often inspired by a saint or virtue that holds significance to the nun personally.
It is a convent
She was born Marie-Françoise-Thérèse Martin and took the name Therese when she became a nun.