The expression 'holier than thou' means

Correct answer: sanctimonious

Explanation: The idiom ‘holier than thou’ refers to someone who acts as if they are morally superior to others, often in a self-righteous or hypocritical way. Pure ❌ – means clean or untainted; not the same. Religious ❌ – means devoted to religion; not exact. Moralistic ❌ – means overfond of making moral judgments, but still weaker than the idiom’s meaning. Sanctimonious ✅ – means making a show of being morally superior to others; perfect synonym for ‘holier than thou’. ✔ Example: His constant advice about honesty sounded holier than thou, making him seem sanctimonious.