Not showing feelings. An unemotional person keeps a flat, calm face and a flat voice even when something big is happening — a death, a fight, very good news. Note carefully: it is about what shows on the outside, not about what is inside. An unemotional man at a funeral may be breaking inside; we only mean that nobody watching could tell. You can also call a thing unemotional, not just a person: an unemotional voice, an unemotional reply, an unemotional description of the accident. Here it means the words carry no feeling — just the facts, said straight. This is where the word gets interesting, because the same behaviour can be praised or criticised depending on who is speaking. A judge, a doctor, a news reporter is supposed to be unemotional, and there it is close to 'fair, not led by feelings'. But say it about a friend, a parent, a partner, and it usually means cold — you wanted them to react and they gave you nothing. English has softer neighbours (calm, cool-headed) and harsher ones (cold, heartless); unemotional sits in the middle and takes its colour from the sentence around it. It is a slightly formal, written-sounding word; in everyday speech people are more likely to say 'he didn't show any emotion' or 'he showed no reaction'.

不動聲色的、面無表情的；(語氣)平淡不帶感情的。注意這是「看不出情緒」，不等於「沒有情緒」，中文若直接說「無情」會太重，那比較接近 cold/heartless。