to think carefully about the advantages or disadvantages of a situation before making a decision

I'm weighing up my options before I decide to apply for the job. 我在权衡自己的选择，然后再决定是否要申请那份工作。

to form an opinion about someone's abilities and character or a situation by thinking about him, her, or it carefully

I weighed up my chances of escape, and decided to wait for a better moment. 估量了一下逃跑的胜算有多大后，我决定等待一个更好的时机。

When you're a detective you learn to weigh people up quickly. 如果你是个侦探，就得学会快速判断一个人。