The area we know as Old Aberdeen today is the approximate location of the first and original Scottish settlement of Aberdeen. Originally the name was Aberdon which literally means "at the mouth of the Don", as it is situated by the mouth of the riverDon.
In reference to Aberdeen, Aber- is pronounced locally as.
Meaning
The prefix; Aber- means the "confluence of waters", "river mouth" or "the embouchure of a river where it falls into a larger river or the sea. It can also be used as a metaphor for a harbour." Aber- is used as a prefix in many placenames in Scotland and more often Wales.
Origin
Aber- is a common Brythonic element, meaning a "confluence". It is presumably that the Pictish language was at least partly P-Celtic as evidenced by various names. Other examples of this prefix in Scotland are Aberfeldy, Aberdour, and Aberbrothick. In Wales, there are frequent examples such as Aberystwyth and Abertawe are examples. Other Brythonic examples include Falmouth, and Aber Wrac'h in Brittany.
Locations
Aber- can be found all over Scotland, predominantly on the east coast. As well as the east coast of Scotland, places with the prefix Aber- or a variant are found all over Wales, on the west coast of England and in Brittany. They are not found on the east coast of England or in Ireland.
''-deen'' end element
The second element is more contentious. It probably refers to Devona, which is a name of one or both of the Rivers Don and Dee, which may also have Brythonic etymologies.
Although the north east variety of Scottish Gaelic has died out, it was present in the region for centuries, as is attested to by Goidelic placenames in the region such as Inverurie, Banchory, Kincorth and Balgownie and was spoken as recently as 1984. The Scottish Gaelic name for Aberdeen is Obar Dheathain.
In 146 AD, Ptolemy wrote that in Celtic times a city named Dēoúana, commonly latinized as Devana, was the capital of the ancient tribal area Taexali. However, although Devana is usually attributed to Aberdeen there is a possibility the capital could have been Barmekyne Hill in Banffshire. The general surmise is that the name Devana refers to a river name. However, there is no consensus which river could be meant, as there are several river names resonating with the Graeco-Roman Devana:
Devana, name of the Denburn and which featured in Ptolemy'sSystem Of Geography of 146 AD;
The Romans and subsequently European scholars and the Catholic Church referred to Aberdeen with various canonical names well into the modern era:
Aberdona
Aberdonia
Aberdonium
Aberdonum
Abredonia
Devanha
Verniconam
Nicknames
Aberdeen also has a number of nicknames, and poetic names:
"The Granite City" – the most well-known, due to the copious use of local grey granite in the city's older buildings.
"Furryboots City" – This is a humorous rendering of the Doric, far aboots?, as in Far aboots ye fae?
"The Silver City by the Golden Sands" or often simply just the "Silver City". Less flatteringly, also "the Grey City". This again is partly due to the granite.
"Oil Capital of Europe" – There are numerous variants on this, such as "Oil Capital of Scotland" etc.
"Energy Capital of Europe" – the "politically correct" name now being used in the city as it tries to project a "greener" image, not based on oil.
The Orkneyinga saga records an Old Norse variant of the name, Apardion, clearly cognate with the modern form.
Unlikely sources
There have been more eccentric etymologies, e.g. Boxhorn considered it Phoenician in origin. This is unlikely, however, as no Phoenician sites have been found this far north.
Residents
Residents or natives of Aberdeen are known as Aberdonians, whence Aberdeen F.C.'s nickname, "the Dons".