Neuter of a derivative of zao; a live thing, i.e. An animal -- beast.
see GREEK zao
1. a living being.
2. an animal, brute, beast: Hebrews 13:11; 2 Peter 2:12; Jude 1:10; Revelation 4:6-9 (on Revelation 4:8 cf. Buttmann, 130 (114)), etc. [SYNONYMS: ζοων differs from θηρίον (at least etymologically; but cf. Schmidt as below) in giving prominence to the vital element, while θηρίον emphasizes the bestial element. Hence, in Revelation as above ζοων is fitly rendered living creature in contradistinction to the θηρίον beast, cf. Revelation 11:7; Revelation 13:1, etc. See Trench, § lxxxi.; Schmidt ii., chapter 70.]