opiate

What it means

1. not comparablemedicineRelating to, resembling, or containing opium.
2. not comparableSoporific; inducing sleep or sedation.
3. not comparableDeadening; causing apathy or dullness.

In a sentence

They chose atheism as an opiate.

1692, Richard Bentley, [A Confutation of Atheism] (please specify the sermon), London: [Thomas Parkhurst; Henry Mortlock], published 1692–1693

Where it comes from

1. Medieval Latinopiātus
2. Englishopiate

From Medieval Latin opiātus.