Having or exhibiting religious reverence; earnestly compliant in the observance of religion; devout. See Synonyms at religious. Marked by conspicuous devoutness: a pious and holy observation. Marked by false devoutness; solemnly hypocritical: a pious fraud. Devotional: pious readings. Professing or exhibiting a strict, traditional sense of virtue and morality; high-minded. Commendable; worthy: a pious effort.