Learner's definition of RELIGIOUS
[more religious; most religious]
1 : of or relating to religion
My religious beliefs forbid the drinking of alcohol.
Religious leaders called for an end to the violence.
2 : believing in a god or a group of gods and following the rules of a religion
She is very religious.
My grandfather was a deeply religious [=spiritual] man.
His wife is very active in the church, but he's not religious himself.
3 a : very careful to do something whenever it can or should be done — usually + about b : very interested in or involved with something — usually + about