/bi wair"/ , v.t.
1. to be wary, cautious, or careful of (usually used imperatively): Beware such inconsistency. Beware his waspish wit.
v.i.
2. to be cautious or careful: Beware of the dog.
[ 1150-1200; ME, from phrase of warning be ware. See BE, WARE 2 ]