🔼The name Arimathea in the Bible
All four gospels make mention of Joseph of Arimathea, a wealthy man in whose tomb Jesus' body was deposited (see full concordance). Joseph was a covert disciple of Jesus (Matthew 27:57, John 19:38) and also a member of the Council (Mark 15:43, Luke 23:50). That gave him enough political leverage to demand an audience with Pontius Pilate, and ask for the release of the Body of Christ (Matthew 27:58).
Joseph was buddies with his fellow Council-man Nicodemus (John 19:39), and partook in the often misunderstood anointing of the Lord's body (which had positively nothing to do with a burial rite and everything with the consummation of a marriage; see our article on Nicodemus for the details). When the men anointed the Lord's body, Mary Magdalene and Mary the mother of Joses and possibly others looked on (Mark 15:47, Luke 23:55).
We don't know much about the place called Arimathea. It's not mentioned in any other context, and the only detail the gospels submit is that it was "a city of the Jews" (Luke 23:51). And that's a peculiar distinction, to say the least.
In the Roman world, the inhabitants of any city could come from all over the place; people were very much accustomed to having foreign neighbors, and likewise, ethnic groups such as the Jews could be found anywhere in the empire. The ethnonym "Jew" didn't so much say anything about where one was from but rather that one was from a family that could prove its ancestral relation to pre-exilic Israelite progenitors (see our article on the name Jew for more details). The indigenous peoples of the Roman province of Judea were collectively referred to as Jews, and Jews created colonies everywhere. To say that someone is from a city of Jews is like narrowing a barn down to a hay loft.
The fact that Luke feels the need to explain where Arimathea was demonstrates that it was a relatively unknown place, but Luke's clarification seems deliberately not clarifying. It seems, therefore, that in the Lucan account and possibly also the others, the name Arimathea does not so much serve as a reference to where Joseph was from geographically, but rather to suggest that Joseph represented an intrinsic quality of the Jewish theological tradition at large. Jesus could have shown up at any time in human history, but in order for Jesus to have a lasting effect on humanity, God needed first to establish a tradition that could recognize him the Lamb, the Messiah and the Son of God. When that tradition was in place, it also produced a segment of its leadership that was (a) wealthy enough to own its own tomb, (b) contemplative of its own imminent death and possibly its own resurrection, and (c) eager to have this tomb first occupied by the Messiah.
Jesus' three day stay in the tomb is as enigmatic as His childhood. We simply don't know what went on in there. But in there, Jesus turned from a single human male into a collective human female: the church. And however that miracle transpired in real time and place, the tomb of Joseph of Arimathea was crucially instrumental.
Also see our article on the astonishing parallels between the death and resurrection of Jesus Christ and the human reproductive cycle.
🔼Etymology of the name Arimathea
There's nothing in Greek that looks like our name Αριμαθαια (arimathea). The first bit, Αρι (ari), could be misconstrued as the common inseparable prefix αρι (ari) or ερι (eri) (see our article on the name Ari), but then we would still be left with the μαθαια (mathia)-part, and that part doesn't occur in Greek. That means that the name Arimathea is probably not Greek.
Certain ancient documents suggest that the name Arimathea was actually pronounced as Harimathea, which has a distinct Semitic ring to it. It thus seems plausible that Arimathea is a Hellenized version of a Hebrew phrase, namely הרמתים (ha'ramathaim). And that phrase consists of the definite particle ה (he), plus a plural form of an ancient way of writing the familiar name רמה (rama), or Ramah. The name Ramah comes from the verb רום (rum), meaning to be high:
Arimathea literally means The Heights. In an attempt to localize Arimathea, scholars have suggested that it may have been the same as the town called Ramathaim-zophim, but that's conjecture. It seems more plausible that Arimathea refers to the most noble qualities of Jewish theology.