a woman who is not married, especially an older woman who is not likely to marry老处女；老姑娘- The sisters were to remain spinsters for the rest of their lives.姐妹们一辈子都将继续生活。
This word should not now be used to mean simply a woman who is not married. compare bachelorOxford Collocations DictionarySpinster is used before these nouns: See full entry Word Originlate Middle English (in the sense ‘woman who spins’): from the verb spin + -ster; in early use the term was added to names of women to denote their occupation. The current sense dates from the early 18th cent.