Paul Y. Hoskisson, with Brian M. Hauglid and John Gee explore possible meanings of the Book of Mormon term “Irreantum” in the Journal of Book of Mormon Studies, Vol. 11, 2002. There are several possibilities, but they present an interesting case that it is derived not from Hebrew but from ancient South Semitic, a language Lehi’s group would have been exposed to during their years in the Arabian Peninsula. The Book of Mormon’s statement that it means “many waters” is actually quite plausible. The construction from Hoskisson et al. points to “watering of (super)abundance” as a possible meaning. Not as straightforward as the Hebrew meaning of Liahona, but still worth considering.
By the way, thanks to everyone that participated in the talk radio show tonight on K-Talk radio. Appreciate all the questions and comments! I had a lot more fun than I did on the first program I did.