There is nothing like a pithy quotation to get the ball rolling, so, in the noble tradition of undergraduates anxious to give the impression of extensive background reading, I have stolen one from a book I have never read.
-- J.K. Rowling, "What was the Name of that Nymph Again? or Greek and Roman Studies Recalled"
Where did the name Hogwarts come from? Rowling answered that question in an interview with the Sydney Morning Herald:
A friend from London recently asked me if I remembered when we first saw Hogwarts. I had no idea what she was talking about until she recalled the day we went to Kew Gardens and saw those lilies that were called Hogwarts. I’d seen them seven years before and they’d bubbled around in my memory. When Hogwarts occurred to me as a name for the school, I had no idea where it came from.
But John Granger, known in fandom as The Hogwarts Professor, who is a great friend of the Lexicon (and someone whose friendship I personally value very highly) has written a wonderful piece for his blog “Hogwarts Professor – Thoughts for Serious Readers” in which he proposes a much more interesting and literary source for the name Hogwarts. His post is, as usual, insightful and extremely well-reasoned and sourced. And, as is also usual, he’s probably right.