Teucer (tyo͞o`sər), in Greek mythology. 1 Ancestor and king of the Trojans, who are also called the Teucri. He was the father-in-law of Dardanus. 2 Son of Telamon and Hesione. He was the greatest archer in the Trojan War and a faithful comrade of his half-brother, the Telamonian Ajax. When he returned home he was banished by his father, who mistakenly thought that Teucer was responsible for the death of Ajax. Teucer went to Cyprus, where he founded the town of Salamis and ruled as king.