Trojan priest of Apollo, from Latin Laocoon, from Greek Laukoun, from laos "people" (see lay (adj.)) + koeo "I mark, perceive."
Laocoön, n. A famous piece of antique sculpture representing a priest of that time and his two sons in the folds of two enormous serpents. The skill and diligence with which the old man and lads support the serpents and keep them up in their work have been justly regarded as one of the noblest artistic illustrations of the mastery of human intelligence over brute inertia. [Ambrose Bierce, "Devil's Dictionary," 1911]
In classical mythology, Laocoon was a priest in Troy during the Trojan War. When the Trojans discovered the Trojan horse outside their gates, Laocoon warned against bringing it into the city, remarking, “I am wary of Greeks even when they are bringing gifts.” (See “Beware of Greeks bearing gifts.”) The god Poseidon, who favored the Greeks, then sent two enormous snakes after Laocoon. The creatures coiled themselves around the priest and his two sons, crushing them to death. Some sources say Athena sent the snakes.