Oh to answer your question specifically, here are the dictionary definitions of the word kukui. You will see that it originally refers to a tree, and its nuts are very oily and were used for lighting because they burned so slowly. That word kukui was then transferred to western type lights.
- Candlenut tree (Aleurites moluccana)
- Lamp, light, torch.
- (Cap.) Star name. (no data)
Thus, turn off the lamp. should be an accepted answer.
My bet is that it is still in beta and some of the bugs like that need to be worked out. Keep in mind that this is a work in progress. Keep posting comments about things like that and if possible report them as well so that it can be updated. I see you have done so many languages and surely you have run into similar things elsewhere.