beware

[bih-wair] /bɪˈwɛər/
verb (used with object)
1.
to be wary, cautious, or careful of (usually used imperatively):
Beware such inconsistency. Beware his waspish wit.
verb (used without object)
2.
to be cautious or careful:
Beware of the dog.
Origin
1150-1200; Middle English, from phrase of warning be ware. See be, ware2
Examples from the web for beware
  • beware of alcohol or other factors that may encourage confessional impulses.
  • beware of boasts by makers of the latest exercise machines.
  • beware of the latest line in less lethal weapons: a scooter equipped with an air gun.
  • Hikers must beware of sudden thunderstorms that can catch them on exposed ridges at any time of year.
  • There will always be those that aren't, but then as with everything: let the buyer beware.
  • And stick to the woods, keep clear of the road and beware of your headlamp.
  • beware of situations in which you are asked to take on all of the less-desirable tasks.
  • beware of rainstorms upstream, since they may cause flash flooding.
  • beware actors for the few trying to sabotage the new system.
  • beware of cheap eateries that sport big color photos of pizza and piles of different pastas.
British Dictionary definitions for beware

beware

/bɪˈwɛə/
verb
1.
(usually used in the imperative or infinitive) often foll by of. to be cautious or wary (of); be on one's guard (against)
Word Origin
C13 be war, from be (imperative) + warwary
Word Origin and History for beware
v.

c.1200, probably from a conflation of be ware (though the compound bewarian "defend" existed in Old English). See wary.