- (defective, transitive, intransitive) To use caution, pay attention (to) (if intransitive, construed with of).
The verb beware has become a defective verb and now lacks forms such as the third-person singular simple present bewares and the simple past bewared. It can only be used imperatively (Beware of the dog!) or as an infinitive (You must beware of the dog or They told me to beware of the dog).
The inflected forms bewares, bewared, and bewaring are called obsolete in Fowler's Dictionary of Modern English Usage, along with the simple indicative "I beware". The forms bewares and bewared are very rarely found in modern texts, though bewaring is slightly less rare. These inflections are more likely to be found in very old texts.
The meanings conveyed by the obsolete inflected forms may be easily achieved by splitting "be" and "ware", conjugating "be", and possibly replacing "ware" with the more modern "wary"; thus, "bewares" > "is wary", "bewared" > "was wary", etc.