The answer to your question can be found in Book IX. For more detail than I can provide here, go to that chapter.
Basically, Polyphemus the cyclops greets Odysseus and his men in a fairly friendly manner, but that doesn't last.
When he sees them in his cave, the first thing Polyphemus asks is who they are. He asks if they are traders or fugitives.
But then he gets a lot scarier. He tells them he cares nothing for the gods because the cyclops are stronger than them. He asks where their ship is.
Then he grabs two of the men, kills them and eats them. And that's how he "greets" them.