Why is the martial art weapon nunchuku called that?

Answer 1

One thought is that the Nunchuku is based on a wheat and grain thrashing tool with a long wood staff small chain and smaller wood staff on other end. Recently it has been shown the it is more closely related to the horse bridle that consisted of two pieces of wood with the bit stretched between.

It goes back to Okinawan Kobudo when they took farming tools and made weapon systems like kama sickles used for cutting rice in the field because the government in feudal Japan would forbid peasants to use weapons.