noun
(Ancient Greece, Ancient Rome, historical) A great public sacrifice to the gods, originally of a hundred oxen; also, a great number of animals reserved for such a sacrifice.
(by extension, religion, historical) A great public sacrifice in other religions; also, a great number of animals or people reserved for such a sacrifice.
(figuratively, literary and poetic) A great number of animals, people, or things that are sacrificed or destroyed; any great sacrifice; also (generally), a large amount.
verb
(transitive) To provide (someone or something) with a hecatomb.