I think that this is the usual definition of "human", but I also think that it doesn't agree with the layman definition of "human". https://en.wikipedia.org/wiki/Human

For a layman, an "human" is a "modern human", i.e. "Homo sapiens sapiens", i.e. me.

There are two difficult problems here. The first is how to classify animals species (including humans, whatever it means). The taxonomy classification is somewhat arbitrary. It's very useful for discussions between biologist, but arbitrary.

For an easy example, what is a kingdom looks like an easy question, but https://en.wikipedia.org/wiki/Kingdom_(biology)#Summary

Currently Homo, Pan, Gorilla or Pongo are different "genus" of the Hominidae "family". (I hope I got all the notation correctly.) The genus is somewhat special, because it's written in the name of the specie, but we could have agree to write the family in the name two. We could have been "H. H. sapiens sapiens" and chimps could be "H. P. troglodytes"

The second problem is that we all agree that the sentence for killing a "human" should be different of the sentence for killing a cow or a pig. But the decision of what "human" means in that sentence is a political one, not a scientific one. Should we consider killing any great apes as bad as killing me? What about other apes? Why? Why must we use the taxonomy classification? What about whales and dolphins? Octopus?