Antinous was the leader of the suitors who were vying for Penelope's hand in marriage while Odysseus was away. He was particularly cruel and disrespectful to Odysseus, even after his return.
When Odysseus revealed his true identity, Antinous refused to believe him and mocked him. Odysseus, disguised as a beggar, killed Antinous with an arrow during the feast in his own palace.