not clearly expressed, known, described, or decided

I do have a vague memory of meeting her many years ago. 我确实依稀记得多年前见过她。

The patient had complained of vague pains and backache. 患者自述说隐约感到疼痛和背酸。

not clear in shape, or not clearly seen

Through the mist I could just make out a vague figure. 透过雾霭，我只能看到一个模糊的身影。

A vague person is not able to think clearly, or gives an impression of not thinking clearly in order to hide their real thoughts.

My aunt is incredibly vague - she can never remember where she puts things. 我的姨妈极其迷糊——她老是记不得自己把东西放在什么地方。

Their report is studiously/deliberately vague on future economic prospects. 他们的报告故意对未来经济前景含糊其词。