Abarim Publications' online Biblical Greek Dictionary
The familiar noun ιππος (hippos) means horse (hence our words hippodrome and hippopotamus, literally meaning river-horse — from hippos and ποταμος, potamos, meaning a flow or river).
Horses were very common animals in Greco-Roman times, but they were used mostly by and associated with the military. Hence the horse doesn't get mentioned much in the New Testament, with the obvious exception of the Book of Revelation (Revelation 6:6-8, 9:7-9, 9:17, 14:20, 18:13, 19:11-21). The only mention of the horse outside Revelation is in James 3:3, where a man's tongue is compared to a ship's rudder and the bit in the mouth of a horse.
Our noun comes with two derivatives:
- The noun ιππευς (hippeus) means horse-man and denotes a mounted soldier (Acts 23:23 and 23:32 only).
- The substantive ιππικον (hippikon) itself derives from the adjective ιππικοσ (hippikos), which literally means "pertaining to (the) horse(s)", but which was also used to denote rank or status of cavalry men. This latter word occurs in the Bible only in Revelation 9:16.
For a look at the astounding parallels between the four horses of Revelation 6 and the four natural forces (gravity, electromagnetism, and the strong and weak nuclear forces), see our riveting article on the Four Horses of Revelation.