vt to ward off.
2. warn ·vt to refuse.
3. warn ·vt to give notice to, of approaching or probable danger or evil; to caution against anything that may prove injurious.
4. warn ·vt to make ware or aware; to give previous information to; to give notice to; to notify; to admonish; hence, to notify or summon by authority; as, to warn a town meeting; to warn a tenant to quit a house.