ADJ-GRADED
无戒备的；无防备的；无警惕的
If you describe someone as unwary, you mean that they are not cautious or experienced and are therefore likely to be harmed or deceived.
例句
With its quicksands the river usually drowns a few unwary visitors every season.
因有流沙，往往每季都会有几个游客不小心在这条河里溺水身亡。