The official Glasgow, Scotland City Council website says that the name comes from the Gaelic 'glas' meaning green, and 'cu', meaning dear or beloved place. I met a man at a party who said he had a first edition of a book on the history of old Glasgow, written by an ancestor of his. Rather cheekily (I was at a party, it was the booze), I asked if I could read it. He definitely wasn't keen. I got the title, and found a company in Montana which sells facsimile prints of old books, and got a copy of it from them.
'Old Glasgow', by Andrew MacGeorge (1880), has it as "… this part of Clydesdale was a Welsh settlement, and the origin of the name is to be sought in the British branch of the Celtic language. It means, I think, the beloved green place – 'glas', viridis, and 'cu' or 'gu', carus, …" (I guess it would have been quite normal, back in 1880, to use latin to define words precisely; my latin dictionary says 'viridis' means green, and 'carus' means dear, beloved).
When I get to the pub and we have exhausted the topics of the day, the sport, the government, markets, celebrities, and so on, conversations often break down into pairs. When the pairs shift, the subject usually shifts too. We have particular aspects of our lives that fit neatly with particular aspects of someone else's, and that's what we like to talk to them about. Tony and I usually talk about do-it-yourself. When we have something to fix at home (and who hasn't?), we can talk endlessly about how the other did, or would, do it, materials to use, tools available, and so on. Tony and Joe often talk about music. If I join in the periphery of one of their musical conversations, it's usually only to derail it so I can talk to Tony about a DIY problem. But Tony is also Welsh: I have an unusual topic for him today: "Glasgow is a Welsh name", I tell him. "'Glas', green …", and before I can get to 'cu', he interrupts: "No, blue", he says. Blue? No, these people can't have got it all wrong. Anyway, 'beloved blue place' doesn't make much sense (unless you're a Rangers supporter; or talking about Glasgow, Kentucky, where the grass is blue, if you let it go to seed). Tony, although Welsh, is not a native Welsh speaker. I tell him he must be wrong. What a nerve! I hijack an interesting conversation about Sibelius' violin concerto (that's the kind of music our pub plays) just to insult his Welsh credentials. It's a good job he's a friend. He remains sure of himself. I see a big hole appearing in my Glasgow story. He goes back to Sibelius
The following evening, Tony's first words are "I was right. It does mean blue. I checked." He's not trying to cheer me up. "However", he goes on, milking the moment, "it also means green". What? That can't be true: it would be a pretty useless language that didn't allow you to differentiate between blue and green. So, at the very next cold-light-of-day, I'm on the internet looking for a Welsh-English dictionary, and, blow me down, the very first one I find, courtesy of the University of Wales at Lampeter, says precisely the same thing, green and blue. It even adds grey, for good measure. The Welsh must be culturally and institutionally colour blind.
I can't bring myself to believe this. I decide to look up MacGeorge's 'viridis', to see if the latin offers any clues. And it does. In the online OED, the search offers all the English words derived from 'viridis'. They all say "… Old French, from the latin 'viridis', green. Not much help of itself, but one of the English words is 'viridian', which is defined as "a bluish-green pigment containing chromium hydroxide". That sounds like an artist sort of word. Artists know about colours. That'll do for me: it's not blue, it's bluish-green. (Alternatively, it's not green' it's greeny-blue.)So Glasgow is a beloved bluish-green place. Which is kind of true, and will certainly cheer up Rangers' supporters. And it will allow the natives to argue, pointlessly, across the sectarian divide, whether it's 'greeny-blue', or bluish-green'.