Cambridge and Collins are wrong! 名 just means name. It doesn't mean English first name. Is it "其名"? I embolded it in Cambridge's example sentence.
the name that was given to you when you were born and that comes before your family name
It can be rude to call people by their first name if they are much older or more important than you. 对年长或级别高的人直呼其名是不礼貌的。
- 名 (míng) (个(個), gè)