What does Irreantum mean?

This unfamiliar name was a source of amusement to some early readers of the Book of Mormon who attributed its origin to Joseph Smith’s creative imagination. Nephi's wording ("which, being interpreted, is many waters") suggests that this may not have been a name from his native language. The name Irreantum, actually yields a plausible eytmology as an ancient South Semitic name meaning "abundant watering of completeness" or "fully abundant waters" which is consistent with Nephi's interpretation of the name.