The name Ngaio is a girl's name of Maori origin meaning "reflections on the water". Ngaio and is often added to lists like Names That Mean Water and discussed in our forums with posts like "Name Your Own Family, Choose Their Family".
From the experts:
Anyone who has ever read the classic mysteries of New Zealand writer Ngaio (born Edith Ngaio) Marsh must have wondered about her name -- and how to say it (NYE-oh). It would certainly make an attention-grabbing if confusing choice.