v.
Pronunciation: bi- ' wer, b ē -
Function: verb
Etymology: Middle English been war, from been to be + war careful ― more at BE , WARE
Date: 14th century
intransitive verb : to be on one's guard < beware of the dog>
transitive verb
1 : to take care of < beware your wallet>
2 : to be wary of <we must ⋯ beware the exceedingly tenuous generalization ― Matthew Lipman>