a kind: one of the recognizable groups into which living things fall
This word names the fact that the living world comes in distinct, recognizable groups: birds, fish, land animals, and within them, this kind of bird and that kind of fish. It is one of the keywords of the opening chapters of the Bible, where it appears over and over to say that the world is ordered, not a blur. Plants, sea creatures, birds, and beasts each come forth "according to its kind."
The word is never used on its own. It always shows up in the same little phrase, "according to its kind," describing how God makes and sorts living things, or later how Israel is to sort them. So it is less a label stuck onto a single animal and more a way of saying "group by group, each true to its own type." The same idea then does practical work in the food laws, where naming one bird or one insect "and its kind" sweeps in the related creatures along with it.
The groups it points to are the broad, everyday ones an ordinary observer would notice, not the precise categories of modern biology. Depending on the passage it can mean something as wide as "all the creeping things" or as narrow as one particular type of locust. Its concern is that creation is bounded and reliable, with each sort reproducing its own sort. It says nothing about how those groups arose or whether they can change over time, and reading either modern evolution or a fixed-species theory into it asks the word a question it was never built to answer.