Akua means spirit or can refer to kūpuna, aumakua, kupua, and kini o ke akua
Akua is a generalized term—it doesn't just refer to the Christian god. It can refer to a variety of spirits and deities. I don't know all these words with confidence, but kupuna are our ancestors, aumakua are specific protective ancestral spirits (some of whom can take animal forms), and kupua are heroic figures from stories (Maui is a good example here). I want to say kini o ke akua are multitudes of spirits and deities, or possibly different facets of a particular deities, but I might be wrong—I wasn't raised in the culture.
I guess it could be either God/dess or deity, but I've read that specifying a Goddess would be "akua wahine" (god-woman), as in "akua wahine Pele" ("Goddess Pele", who is the volcano deity who created Hawaii).
According to Wikiditionary, akua can also mean "spirit" or "ghost", although it's probably most common to translate the word to "God" because how it's used religiously.
People do not refer to Pele as an akua wahine really, just as an akua. In fact, I have never heard anyone use the compound noun akua wahine to mean goddess. That seems to be forcing the cultural construct of goddess vs god upon the language.
Your wiki is right, these guys are teaching the christian verson of hawaiian culture
This section has a decidedly Christian slant to it. The implication here is clearly God meaning the one from Ka Paipala Hemolele instead of any original meanings and nuances.
Akua refers still to the original Gods of Hawai'i like Kanaloa and Lono and such.
He aha ka huaʻōlelo no God? = What is the word for Akua?
New Hawaiian Dictionary
God, goddess, spirit, ghost, devil, image, idol, corpse; divine, supernatural, godly. Akua might mate with humans and give birth to normal humans, moʻo, or kupua (Nānā 23). Children of Kamehameha by Keopuolani were sometimes referred to as akua because of their high rank. Kauā, or outcasts, were sometimes called akua because they were despised as ghosts.
That reads practically verbatim from the Puku'i-Elbert dictionary, which is copyrighted. Does the University of Hawai'i Press know about this new dictionary that is so close to their own?
According to (Manomanoʻs) page they were "Created by KAI LOA Inc, with funding by the U.S. Department of Education Native Hawaiian Education Programs Grant, HOOPAEPAE (S362A150055)".