Definition & Meaning of "a pain in the neck"in English

What is the origin of the idiom "a pain in the neck" and when to use it?

"A pain in the neck" is an English idiomatic expression that dates back to the early 20th century, used figuratively from the literal discomfort of a stiff or sore neck. It came to describe a person or thing that is very annoying, troublesome, or irritating. The phrase is used in informal speech, everyday conversation, and writing to convey mild frustration or complaint. It is not vulgar and is generally considered a light, socially acceptable way to criticize someone or something.