I personally think it's a rotten idea...是什么意思？

I personally think it's a rotten idea...

我个人觉得这个主意非常糟糕。

personally

adv. 亲自地，就个人而言，个别地，私人地（与工作相对）；

例句
No-one personally acquainted with the couple was permitted to talk to the Press...
任何与这对夫妇有私交的人都不准和新闻界谈话。

think

vt. 想，思索，以为，看待；vi. 思辩，考虑，构想，回忆；adj. 深思的，供思考的；n. 想，想法；

例句
I think there's something a little peculiar about the results of your test.
我认为你的化验结果有点不对劲。

rotten

adj. 腐烂的，恶臭的，堕落的，极坏的；adv. 非常，极其；

例句
Most Canadians acknowledge that the aboriginal people have had a rotten deal.
大多数加拿大人承认土著居民遭受了不公平的待遇。

idea

n. 主意，想法，[哲]理念，观念，[乐]乐句，模糊想法；

例句
It is often a good idea to start with smaller, easily achievable goals.
一开始把目标定得低一点、容易实现一点，总不失为一个好主意。