ADJ-GRADED
無戒備的；無防備的；無警惕的
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，往往每季都會(huì)有幾個(gè)游客不小心在這條河里溺水身亡。