A god is a male deity, in contrast with a goddess, a female deity. While the term "goddess" specifically refers to a female deity, the plural "gods" can be applied to gods collectively, regardless of gender.
In most polytheistic religions, both in history and in the present, male deities had the more prominent role. The Greek and Roman pantheons were ruled by Zeus and Jupiter.
When Ancient Egyptian religion developed closer to monotheism, it was Amun, a male god, who rose to the most prominent place.
War gods, like the rulers of the pantheon, could often be male, such as Ares/Mars and Toutatis.