The word moala refers to a type of yam in Tonga. Moala Island is an place in Fiji. In this case Moala possibly originates from Fijian mua la meaning "follow the bow of the canoe". In Hawaiian and Samoan mo'o ala means "lizard path".
Possibly a variant of Malu meaning "safe place, refuge; calm, peaceful" in Samoan and Tongan. Also possibly a variant of le ala meaning "the path" in Samoan, or alaimaluloa meaning "path in the shade" in Tongan.