Think of the term 絕世高手 (Master out of this world/ extraordinary master); 绝代美女 would mean (Beauty out of this generation). Which means you may only see beauty like this once in a generation. It is an exaggerated adjectival phrase, a more realistic version of this phrase would be 'top class' or 'extraordinary' *Exaggerated adjectival phrase is very common in Chinese, for example, 惊天 (shock heaven) is an exaggerated phrase for "shocking"; 万能 (ten thousand usage) is an exaggerated phrase for "multi-functions"* "太多绝代美女" means "there are so many extraordinary beauties " As for your question, depend on the context, "什么叫" can mean "what calls" (with "what" as the subject) or " what is called" (with what as the object) In this context : "什么叫绝代美女?", she is asking "what is called extraordinary beauties?" The difference: - "什么叫绝代美女?" (what is called extraordinary beauties?) is asking what qualified someone as an extraordinary beauty (asking for your opinion, implies some doubt) - "什么是绝代美女?" (what is extraordinary beauties?) is asking what is the definition of extraordinary beauties (asking for a definite definition) Since you claimed Ukraine have many 绝代美女, she was asking you to make clarification on this statement. She knew what the term '绝代美女' means-- "an extraordinary beautiful woman; a rare beauty"