weak-minded 意志薄弱；优柔寡断的；低能的

【例句】
She can't make a decision quickly because she's a weak-minded person.
她不能很快下决定，因为她很优柔寡断。

Stress sometimes is really a great trouble to those weak-minded person.
压力的确对有些意志薄弱的人构成了很大的麻烦。