Yeah, nui is close, but sometimes certain things are done in certain ways. I'm not real clear on all the different aspects. For instance manu is bird. manu nui is a large bird, while nui manu is a flock of birds. Wiki is fast, wiki wiki is very fast. I'm not positive, but I think nui is used with nouns, while doubling is used with adjectives and verbs. Again, I'm not an expert in Hawaiian language. Much of what I know has come from songs. This line comes from a song called Henehene Kou `Aka:
Ka`a uila makeneki
ho`oni oni kou kino
in English: "The street car wheels turn
vibrating your body"
oni is doubled here,indicating a lot of shaking. Oni has multiple meanings, used for similar though not quite identical words. Actualy, this is where Mrs. Wanda got the name for oni. It's a favorite song of hers.
Could get close, I guess by adding 'nui' ... as in "malihini pupula nui". Nui being much or very much if memory serves. I like Oni Oni better though.