The noun βαρος (baros) means weight or heaviness, the opposite of ελαφρος (elaphros), light or light-weight. It stems from the Proto-Indo-European root "greh-", meaning heavy, from which also stems the familiar Latin words gravo, to be heavy, and gravitas, heavy, from which comes our English word gravity.

The Germanic word "baron" is thought to not technically derive from this same root, but obviously became grafted on it because it fitted right in. The word barony initially described society's first and only nobility: the property-owning class that the rest of society worked for. In time, the initial property-owning class was superseded by even higher ranks (the bosses who owned the barons), which is why in later times the word barony came to describe society's lowest property-owning class: those who directly employed the common no-haves, and thus the only sort of nobility the common masses would ever experience. It is rumored that in our modern world, our visible presidents and their governments are merely baronial, and themselves wholly governed by much higher higher-uppers, who are utterly invisible to the average Joe.

In the Greek classics, our noun βαρος (baros) could describe literal heaviness (a weight, burden or load), but also the burden and oppressiveness of troubles, pain and grief. In a positive sense, our word could convey abundance and strength, or one's "weight" in society, one's influence, status and clout. In that sense, this noun is not unlike the Hebrew word כבד (kabed), which also means both literal weight (of a boulder) and societal gravity (of some baronial lord). Note that the word כבד (kabed) also describes the visible "glory" of our otherwise invisible God.

In the New Testament, our noun is used only in the sense of a perceived weight or burden, rather than something physically heavy. It's used 6 times, see full concordance, and from it derive:

The familiar adjective βαρβαρος (barbaros) means barbarous (i.e. pertaining to barbarians), but where in English our word associates with brutes and heathens (and perhaps with beards and barbers, or even Berbers), in Greek it naturally associates with βαρος (baros), heaviness or burden (see above). There was also an adjective βαρβαροφωνος (barbarophonos), or barbaro-sounding (unused in the New Testament), which either referred to Persians speaking Persian, or else anybody very bad Greek.

The closely similar Italian name Barbarossa (given to German emperor Frederick by Italians) comes from barba, beard, and rossa, red. The similarity between this term and our word βαρβαρος (barbaros) is entirely accidental. They mean widely different things.

In a strict etymological sense, our word βαρβαρος (barbaros) is thought to be onomatopoeic and imitative of foreign bla-bla (or in this case: bar-bar). But the verb γογγυζω (gogguzo) is also thought to reflect foreign bla-bla, or more precise: gonk-gonk. And then, of course, the Greeks and their many neighbors all did business with each other (Cleopatra spoke nine languages and was no shocking exception), and everybody was always quite used to hearing a wide variety of languages and dialects. Or in Homer's description of Troy: "Numerous here are the allies spread out in Priam's great city, men from many lands, all speaking different tongues" (Il.2.803-804; compare 1 Kings 10:24 and Acts 2:9-11). All this makes it seem unlikely that the Greeks had a derogatory word for Auslander based on how their speech sounded.

Much more likely is a natural connection to βαρος (baros), meaning that a barbarian, or barbaro-phone, was proverbially difficult to understand, which made trading with such a person a troublesome but lucrative affair.

Any society with sense to speak of (and back then, that was most of them) also knew that a healthy influx of strangers was crucial to society's diversity, its international connectedness and thus ultimately its prosperity, security and bliss. The Hebrew Torah had even specifically incorporated hospitality to aliens into the core legislation of Israel (Exodus 22:21), and even insisted that the same laws applied to natives and visitors (Exodus 12:49). That suggests that our adjective may even have been named after the importance aliens have within society, much rather than the burden that some linguistically challenged members of society might experience from their presence.

Also note that a society's legislative government (its king) was called its father (which is also why God is our Father), whereas the general population was called the mother. Any single member of society was called its son. In Hebrew that is the noun בן (ben), which associates to the verb בנה (bana), meaning to build (a house). The Aramaic equivalent of the Hebrew word בן (ben) is בר (bar), which was a broadly recognized word in the ancient word (judging from the many names its part of). That means that βαρβαρος (barbaros) also means son of weight, or important son.

Our adjective βαρβαρος (barbaros) is commonly used substantially and simply means hard-to-understand foreigner (1 Corinthians 14:11). It occurs 6 times in the New Testament; see full concordance.