In Greek mythology, Host was the husband of Alcmena, Hercules' mother. He was the brother of Anaxus, wife of Electrian, and Perimede, wife of Lycimnius.
While Host was at the war of Thebes, Zeus took his form to lie with Alcmena, and Hermes took the form of his slave, Symia, to set guard at the gate.
A great confusion was created, for Host doubted his wife's fidelity. In the end, everything was cleared up by Zeus, and Host was happy to be the husband of a chosen one of the god.
From that night of love, the demigod Heracles was born. From then on, the term host came to have the meaning of "one who receives at home. The same happened with look-alike, "human copy", that is, human resemblance.