%beware%

v. i. [ Be, imperative of verb to be + ware. See Ware, Wary. ] 1. To be on one's guard; to be cautious; to take care; -- commonly followed by of or lest before the thing that is to be avoided. [ 1913 Webster ]

Beware of all, but most beware of man ! Pope. [ 1913 Webster ]

Beware the awful avalanche. Longfellow. [ 1913 Webster ]

2. To have a special regard; to heed. [ Obs. ] [ 1913 Webster ]

Behold, I send an Angel before thee. . . . Beware of him, and obey his voice. Ex. xxiii. 20, 21. [ 1913 Webster ]

☞ This word is a compound from be and the Old English ware, now wary, which is an adjective. “Be ye war of false prophetis.” Wyclif, Matt. vii. 15. It is used commonly in the imperative and infinitive modes, and with such auxiliaries (shall, should, must, etc.) as go with the infinitive. [ 1913 Webster ]