Abarim Publications' online Biblical Greek Dictionary
The two prefixes αμφι- (amphi-) and αμφο- (ampho-) are obviously related. Both stem from the idea of converging on one point from a position of dispersal (and as such are related to the Hebrew verb בוא, bo').
The prefix αμφι- (amphi) describes a surrounding, and can usually be translated with round or roundabout; think for instance of the word amphitheatre, which is a round or circular theatre. This particular prefix was replaced by περι (peri) in later Greek.
The prefix αμφο- (ampho) describes an approach from both or all sides, and can usually be translated with both or even two; think of the misspelled adjective amphibious, which means living both in water and on land, or the noun amphora, which is a two-handled vessel, or the adjective amphoteric, which means acting in both ways, and specifically: having both acidic and basic properties.
Our prefix also exists in Latin, namely as ambi-, meaning "both" in our words ambivalent, ambiguous and ambidextrous, and "round/surround" in words like ambiance and ambience.
In the Greek New Testament, the following compounds that make use of our prefixes occur:
- Together with an expression of the verb βαλλω (ballo), meaning to throw: the noun αμφιβληστρον (amphiblestron), literally meaning a thing that's thrown round or round thing that's thrown. It denotes the kind of fishing net that a person would throw onto the water from the shoulder in a roundabout sweep (Matthew 4:18, Mark 1:16).
- Together with the otherwise unused verb εννυμι (ennumi), meaning to invest: the verb αμφιεννυμι (amphiennumi), meaning to wrap (oneself) in clothes (Matthew 6:30, 11:8, Luke 7:25, 12:28).
- Together with the noun οδος (hodos), meaning road or way: the noun αμφοδον (amphodon), which may denote a place where two roads meet, or else an urban area surrounded by a circular road (Mark 11:4 only).
- The noun αμφοτερος (amphoteros), meaning each of two. In plural this noun means both (Matthew 9:17, Luke 1:6, Acts 8:38, Ephesians 2:14).