flying creatures as a class: birds and other winged animals, taken together
This is a collective word. It does not name one bird but the whole category of creatures that fly, which is why English Bibles often render it as a group, "the birds of the air" or "the fowl of the heavens." The Hebrew sorts animals by how they move rather than by modern biology, so the deciding trait here is wings and flight, not feathers.
That is why the word can reach beyond birds. In the food laws it stretches to cover winged insects, the things that fly and also crawl, which the same passages set apart from clean birds. The two senses below are not two different words but the two edges of one class: ordinary winged life on one side, and the swarming winged insects on the other.
Because it is collective, it usually appears as a sweeping category, the birds set over creation, the birds that scatter or are scattered, the birds that feed on the dead. Where a single bird is in view, the Hebrew tends to reach for a more specific word instead.