Etymology of the term お局 and how it is used in slang

Question

Can someone explain the etymology of the word お局 as well as how it is used in modern slang? I took an educated guess as to the colloquial meaning but am unsure of its nuances, be they comedic, insulting or otherwise....

お局に小言を言われることにうんざりしている。

I’m sick of being scolded by “otsubone.”

局: bureau; board; office; affair; conclusion; court lady; lady-in-waiting; her apartment;

colloquial: an older single woman in a man's world/a term used to scornfully describe an unmarried veteran female employee [?]

Answer 1

The etymology is prefix o + noun tubone (局). A tubone is a "room" in a large building. These rooms were primarly prepared for women who served at noble or imperial residences. The term has been around since around the 14th century.

Historically, an otubone was a woman who served at the imperial court and given a "room" (局) of her own. During the Edo period, the otubone was the one responsible for managing the women who served in the 大奥.

In modern Japan, there is no longer an 大奥, and the meaning has changed to express a woman with some power who has been working for a long time. Until recently, women in Japan were expected to quit their jobs once they got married, so an otubone would be assumed to be single.