“剩女”可以说成：
1. single woman over 27/unmarried female above the age of 27
2. leftover woman
第1种翻译是意译，但是“剩女”的年龄到底是27还是28或是其他，见仁见智，不绝对。
第2种翻译是直译，其中leftover一词和中文的“剩”精确对应，Longman Dictionary of Contemporary English对leftover的解释是：remaining after all the rest has been used, taken, or eaten。
如果想向外国人精确传递“剩女”的含义，建议这样说：
“Shengnu” literally means "a leftover woman". It refers to a single woman who is above the age of 27. “剩女”的字面意思是“被别人选剩下的女人”，用来指过了27岁的单身女性。
以下是来自于BBC官网的文章(节选)，供大家参考：
Emotional advert about China's 'leftover women' goes viral
By Heather Chen
8 April 2016
Single women over 27 in China are known as "leftover women"
The issue of unmarried females, often stigmatised as "sheng nu" or leftover women, has long been a topic of concern in a society that prioritises marriage and motherhood for women.
By government definition, a "leftover woman" refers to any unmarried female above the age of 27
