Mate is a word that brings to mind one of two things: 1) sailors, 2) Australians. Guess which one we'll be talking about here.
The word mate meaning a friend or comrade has various etymologies, but three stand out for me as more likely than the rest. The first is the most simple and straight forward (so, probably, the most likely as well). Mat (pronounced with the hard a sound) was the Saxon word for fellow and could be used in place of brother. OK. But what if...
The French word for sailor is matelot and has been for hundreds of years. This is the "common sailor" that one would picture in petticoat breeches and bare feet with a dewrag on his head and a deep tan. It stands to reason that the word might be shortened to mate by the men who were matelot and/or by their English comrades/enemies who just didn't have an ear for Latin languages. But there is another word - specific to pirates - that may have had an influence on the English usage of the word today.
In the early days of the boucaniers, first on the island of Hispaniola and then on Tortuga, the men who learned to smoke meat and cover themselves in animal fat to keep off the mosquitoes were pretty lonely. Yep. The first buccaneers were an all dude society. The displaced and runaway indentured servants had only each other to count on. In the early 17th century, most of these guys were French so that was the language spoken. They tended to live in groups of six to eight and they set up rules among themselves for the sharing of food, water and - as the first raids on Spanish shipping began - other goods as well.
Some of the boucaniers formed pair bonds that may or may not have been homosexual depending on the men involved. These unions were known as matelage, which is sometimes erroneously interpreted as meaning "marriage". In fact, the meaning is closer to a "companion" or even "pal" who was a fellow sailor. The age at the end of the word refers more to the practice than the relationship. (A similar example would be the Louisiana Creole word placage, technically meaning "placement" but referring to a contracted, near marriage between a white man and a "free woman of color".) The matelage system continued when women came to Tortuga with two already bonded men sharing a "wife". Lucky girl.
So there , mates. You've a few etymologies to choose from. Pick the one you like and stick with it. Your humble hostess is on the good ship matelage herself. It just sounds right.
(By the way, the picture at the header is of the Beaufort, N.C. fire department circa 1960 reenacting a pirate invasion of the town in 1747. If you'd like to know more about Beaufort and her seafaring history, click here to check out the town's fabulous blog.)