Final answer:
Odysseus gave the name "Nobody" to himself to trick the Cyclops Polyphemus in Homer's epic, enabling him and his men to evade capture and potentially certain death.
Step-by-step explanation:
The name Odysseus gave to himself when encountering the blinded Cyclops was "Nobody". The story behind this alias comes from Homer's epic poem, The Odyssey, where Odysseus encounters the Cyclops Polyphemus on his journey home from the Trojan War. Employing quick wit and cunning, Odysseus introduces himself as "Nobody". When he and his men blind Polyphemus, the Cyclops screams for help, claiming that 'Nobody' is hurting him, which results in no assistance coming from the other Cyclopes, as they believe nobody is attacking him. This clever play on words saved Odysseus and his men from immediate danger, allowing them a chance to escape.