Here are the two main theories:
* Lime Juice: This is the most common theory. British sailors were given limes to prevent scurvy, a disease caused by vitamin C deficiency. This practice started in the 18th century and continued throughout the 19th century. The nickname "limey" is thought to have originated from the sailors' consumption of lime juice.
* Limewashing: Another theory suggests the word "limey" originated from the practice of limewashing the hulls of British ships. Lime was used as a disinfectant and to prevent barnacles from attaching to the hull.
While the exact origin remains uncertain, the term "limey" became a common slang term for British sailors and later for British people in general. It is considered a somewhat outdated term, though it is still used occasionally, often in a lighthearted manner.