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.
To give notice to, of approaching or probable danger or evil; to caution against anything that may prove injurious.
notify of danger, potential harm, or risk; "The director warned him that he might be fired"; "The doctor warned me about the dangers of smoking"
admonish or counsel in terms of someone's behavior; "I warned him not to go too far"; "I warn you against false assumptions"; "She warned him to be quiet"
notify, usually in advance; "I warned you that I would ask some difficult questions"