Definition & Meaning of "a hair out of place"

What is the origin of the idiom "a hair out of place" and when to use it?

The idiom dates back to the early 19th century, where a hair that was out of place was seen as a sign of disorderliness or carelessness. In the Victorian era, when rigid social norms governed behavior and appearance, a hair out of place was a visible indication of someone's failure to conform to these standards. The idiom is still commonly used today to describe someone's appearance that is not perfect or as expected, implying a lack of attention to detail or a sense of disorderliness.