How do you name the phenomenon of being single at a late age?

Question

Specifically, a woman who is single at a late age. "Late bachelorette", "late singleness"... It doesn't sound right.

Is there a way to describe it as an adjective and also as a noun?

I am asking because I am trying to translate an article from another language.

Edit: After reading the commenmts, I understand that some further clarification is needed. I was trying to find a term for someone who has never been married and has already passed the "culturally accepted marriage age" for lack of better term.

I was looking for a descriptive, nonjudgmental and nonpejorative term. The term I was trying to translate was originally in Hebrew - רווקות מאוחרת, which according to Google Translate, translates to Late bachelorhood but I wasn't sure it is correct.
I understand that this is a highly cultural dependent question that carries some weight and was looking for various options from multiple English-speaking cultures.

The article I was reading, by the way, was about people in modern societies choosing to stay single even after the "culturally accepted" marriage age and the various reasons behind it.

Answer 1

If you mean those who have never married, you can hyphenate it. The Social Security Administration (SSA) uses never-married as an adjective (never-married retirees) and the never-married as a noun, an adjectival noun (like the poor or the elderly).

This article focuses on a growing yet understudied subgroup of the elderly in the United States—the never-married. The first section, based on data from the Current Population Survey and a review of the academic literature, examines the current circumstances of never-married retirees, particularly their economic and health well-being.

[ssa.gov]

Answer 2

The traditional term for a woman who has never been married is "spinster". While it technically applies to women of any age, it is more associated with older single women. It's not frequently used these days because it carries some bad associations, but it does accurately describe the situation you are talking about.

Answer 3

Old maid :

AHD old maid

noun 1. (Offensive) Used as a disparaging term for a woman who is no longer young and has not married.

adjective old-maidish

(The word maid without old can refer to an unmarried girl or woman, per AHD.)

Answer 4

To be neutral and objective, you could simply use unmarried (if you consider only (formal) marriage) or single (if you want to possibly include non-married partners), and leave the age aspect to the context, implicit, or omitted.

Answer 5

For men, there is "confirmed bachelor", which is not pejorative. Just means that the guy has never been married, and does not seem to be on any trajectory to ever get married.

(There is also the idiosyncratic "Norwegian bachelor farmer" concept which played a recurring role in Garrison Keillor's "Prairie Home Companion". The phrase referred, as might be obvious, to a certain kind of single man living out in the country... perhaps having few interactions with any people at all, much less any potential spouse... of any sort.)

It may be worth noting that many of the historical instances of people living their lives without marrying anyone were cases of gay or lesbian people who had to hide their actual personal relationships due to (justified) fear of punishment. In particular, except for historical purposes, it might be misguided to really think in terms of "never married", when all it was was "not being allowed to marry the person you love".