Something ambiguous is unclear because it can be understood in more than one way. An ambiguous sentence, smile, or rule leaves you asking which one they meant.

Something ambiguous某樣東西是ambiguous的 is unclear就是不清楚 because it can be understood in more than one way因為它可以有不只一種理解方式。An ambiguous sentence, smile, or rule一個ambiguous的句子、微笑或規則 leaves you asking which one they meant會讓你搞不清楚對方到底是什麼意思

It is a little formal, but educated speakers use it often.

It is a little formal這個字有點正式 but educated speakers use it often但受過教育的人常常在用

We do not usually call a person ambiguous in everyday English — that can sound as if the person themselves is unclear, or even a bit shifty. We call their words, signals, or position ambiguous.

in everyday English在日常英文裡 We do not usually call a person ambiguous我們通常不會說一個人是ambiguous — that can sound as if the person themselves is unclear, or even a bit shifty這樣講聽起來像是那個人本身不清不楚，甚至有點鬼鬼祟祟。We call their words, signals, or position ambiguous我們會說的是他們的話、訊號或立場是ambiguous

Though actually, people stretch it to mean vague or I don't get it, even when there are not two real readings, only fog. Strict teachers prefer to keep it for the two-way kind of unclarity.

Though actually不過其實 people stretch it to mean vague or I don't get it大家也會把這個字延伸來說「含糊」或「我聽不懂」 even when there are not two real readings, only fog即使根本沒有兩種真正的解讀，只是模糊一片。Strict teachers嚴格一點的老師 prefer to keep it for the two-way kind of unclarity比較堅持只用在那種「有兩種解讀」的不清楚