The adjective χιλιοι (chilioi) means a thousand, but note that in the first century, people didn't maintain as strict an arithmetic standard as we do today. There weren't many instances of the number thousand (one thousand of the same things is quite rare in the real world) and when such a thing occurred, it was rarely necessary to precisely count them.

Our word is thought to derive from the same Proto-Indo-European term "ghes-", meaning heap or hand, as the noun χειρ (cheir), meaning hand. In other words: our adjective χιλιοι (chilioi) rather means "a whole bunch; probably somewhere near ten groups of roughly a hundred each".

Our word χιλιοι (chilioi) appears 11 times in the New Testament, all but once in Revelation; see full concordance. Also see our article on μυριος (murios), from whence stems our English word "myriad".

Our adjective χιλιοι (chilioi) has one true derivation, namely:

The noun μιλιον (milion) is a Latin word that refers to the Roman mile, which was named after the term mille passus, or a thousand steps (or "feet"; hence the English verb "to pass").

Since this word is Latin, it's not common in the Greek classics — the Pontic geographer Strabo used it a few dozen times, but he wrote during the Empire's first decades and clearly aimed to cater to his Roman patrons. In the New Testament, our noun occurs in Matthew 5:41 only, where Jesus speaks of someone pressing someone else into walking a Roman mile. This implies that the first person would be a Roman, and that means that this statement is applicable to the whole of the Roman occupation, and ultimately extendable to all empire, and hence all rebellion. It's part of the New Testament's central advice to always resist evil wisely (Luke 6:27, Romans 12:20), to never battle it on its own terms (Romans 16:19-20), and certainly never by bringing a knife to a gunfight (or sticks to a sword fight), trying to reason with a pack of guard dogs (Matthew 7:6) or provoke them into what they are trained to do without question or remorse (Titus 3:1).

Our noun μιλιον (milion) is the source of our English word "million", which indicates that this word was generally considered to mean "a whole lot" rather than specifically one thousand. Evidently, our word can be constructed from the PIE elements "sm-", meaning one, "-ih", the feminine suffix comparable to the Hebrew ה (he), "ghes-", heap or hand (hence χιλιοι, chilioi, a thousand; see above), plus once again "-ih", the feminine suffix.

However, in our article on the many Hebrew roots of Greek, we point out that the language of the Greeks was strongly influenced by their Semitic trading partners, who gave them the alphabet and a whole slew of handy terms to jump-start the wisdom tradition that they would become so famous for. One particular Hebrew word of interest is the verb מלא (male'), meaning to fill or be full. This verb mostly speaks of storage facilities that are filled with whatever was extracted from the land that produced it: nouns מלאה (millu'a) and מלאת (mille't) denote the filling of gold objects with ornamental jewels. From this verb מלא (male') comes the important name Millo, which described (probably) the treasury attached to the fortress of Zion in Jerusalem.

In 1 Kings 11:27 we read: "Now this was the reason why [Jeroboam, son of Nebat] rebelled against the king: Solomon built the Millo, and closed up the breach of the city of his father David."

That rebellion caused the loss of the United Kingdom of Israel, which turned one stronghold into multiple much weaker centers, and ultimately resulted in the dispersal of most of House Israel into Europe, and Judah's exile into Babylon. And that's not where this stops. Israel's arch-nemesis the Amalekites (with whom later Rome and later still the Nazis became identified), were descendants of Esau, Jacob's twin brother, with whom he was once firmly united. Had it been possible for Jacob to maintain the peace with his brother, he may have been spared a world of pain. Likewise, the otherwise inexplicable rise of centers of baffling cultural sophistication in barbaric Europe (Scotland, Scandinavia, the Gaul; see our article on βασκαινω, baskoino, bewitch) seems to have coincided with the disappearance of the northern tribes of Israel. This has led a host of modern enthusiasts to suspect that these two events may have had something to do with each other — and despite its modern popularity, traces of this hypothesis can be clearly found in the New Testament: see our articles on the names Phoenicia and Spain.

In our article on the noun μεμβρανα (membrana), we discuss Paul's curious request for Timothy to come to Rome but first swing by Carpus in Troas to pick up his cloak, his papers and his "skins" (2 Timothy 4:13). In other words, Paul says "let the writings come to me [in Rome]", the way Jesus said "let the children come to me [in Judea]" (Matthew 19:14). Everybody in Paul's original audience would have known that the term "Carpus of Troas" translates as "the Fruit of Troy", and that Virgil in his masterful epic The Aeneid had firmly established that the Roman imperial elite had descended from the surviving Troyan prince Aeneas — whom Luke depicts as a paralytic of eight years (Acts 9:33), which is an obvious play on the name Octavian (means Eighth), the original name of Rome's inaugurative emperor Augustus.