Rule of Thumb

The phrase "rule of thumb" is often misunderstood, with many believing it originated from a medieval law regarding domestic abuse. However, this urban legend lacks historical evidence, as the term actually dates back to the 17th century, referring simply to an approximate method of measurement. The confusion stems from a rumor about a judge in the late 18th century, but the true meaning and origin of the idiom have been misrepresented over time.