Hi \hi\ as a boy's name is a variant of Hiram (Hebrew), and the meaning of Hi is "my brother is exalted".
The baby name Hi sounds like Hai and Hy. Other similar baby names are Si, Bo, Cai, Haim, Hiro, Honi, Cy, Dai, Hadi, Haig, Hal, Hali, Ham, Hani, Han, Hari, Hill, Hob, How, Huw, Hew, Jai, Jo, Kai, Le, Mo, O-, Pio, Rai, Rei, Rio, Roi and Ty.