Antonyms of adj sanctimonious

1 sense of sanctimonious

Sense 1
holier-than-thou, pietistic, pietistical, pharisaic, pharisaical, sanctimonious, self-righteous -- (excessively or hypocritically pious; "a sickening sanctimonious smile")

INDIRECT (VIA pious) -> impious -- (lacking piety or reverence for a god)

Similarity of adj sanctimonious

1 sense of sanctimonious

Sense 1
holier-than-thou, pietistic, pietistical, pharisaic, pharisaical, sanctimonious, self-righteous -- (excessively or hypocritically pious; "a sickening sanctimonious smile")
       => pious (vs. impious) -- (having or showing or expressing reverence for a deity; "pious readings")