Near-human are a group of species that are extremely similar, if not identical, to humans. Some use this term to refer to humanoid lifeforms that don't originate from Earth, though technically humans themselves could be counted as a near-human race.
Atomic Roger seems to be a near-human, though he appears so, he seems to have little actual knowledge of everyday life on Earth. Maximus presumably assumed that Atomic Betty was near-human, as he didn't believe she was from Earth despite her obviously human appearance. (No Space Like Home)