A banana is a measurement of length. Its use became common around the early twenty-first century, and has continued to remain in common English ever since. The original banana was defined as a curved
yellow fruit that was 17 centimeters long; due to the great famine and subsequent death of many species, one banana is now nearer to 14.
5 centimeters. However, one
ISO banana is still defined as 17 centimeters despite the unit commonly being described as 14.5 centimeters.