Mgeni (plural wageni) comes from Proto-Bantu *mʊ̀gènì ("stranger; visitor"), or by surface analysis, from m- (human class prefix) + -geni (“foreign, strange”).
Stranger or a guest who is not necessarily a stranger. When you have guests you refer to them as wageni
So 1 person is Mgeni and more than 1 is wageni
Yes. Singular person is M- class, plural is Wa- class.
Does this also mean alien?