Sheng nu cites studies that show that women are now breaking the tradition of "mandatory marriage" to have fewer children or marry later on in life. Other typologically similar terms that are still used in the modern lexicon of other countries and cultures show the concept has existed in some cases as far back as the 16th century. The term spinster was used to describe unmarried or single women of a marriageable age. It wasn't until 2004 when the Civil Partnership Act replaced the word spinster with "single" in the relationship history section of marriage certificates in the UK. Subsequently, at the
Spinster this sense "is ... perceived as insulting. It implies negative qualities such as being fussy or undesirable". Also included is a sense of the word used specifically in a legal context: "a woman who has never married". Wordreference.com describes the "woman still unmarried" sense of 'spinster' as "dated". Age is a crucial part of the definition, according to Robin Lakoff's explanation in "Language and Woman's Place". "If someone is a spinster, by implication she is not eligible [to marry]; she has had her chance, and been passed by". "Hence, a girl of twenty cannot be properly called a spinster: she