Thorn, barb, spine, bur; barbed, thorny, prickly, burry; jabbed, pricked, hurt by a thorn.
Now this is a small kid time word. And because of the pain involved when stepping on a kukū, I think it's a word being perpetuated to the next generation. At least for the people living in Hawai'i. We get all kine kukū over here. Remember that small kukū hiding in the grass? Da bugga stuck to your long pants or your shoe string or if you get one towel, auē, they all come on top da towel and hard for get 'em out! Not only dat kine! Get the kiawe tree kukū. Talk about 'aui! das one sore one, right tru da rubba slippa an' all!
In old Hawai'i the only thing you can get pricked with, besides a speartip, would probably be the wana. Other than that, plants in old Hawai'i had no thorns. Because of the pristine environment and lack of predators many of the plants here did not need to have thorns for protection.
Akahele i ke kukū ma ka pā hale - Watch out for the kukū in the yard.
'Eha maoli ke hehi 'oe ma ke kukū - It really hurts when you step on a kukü.