Alastor - Greek God who sought revenge on people.
Albus - In Latin means white (maybe for white beard). Wisdom. Or.. Governor of Britain at the death of the emperor Pertinax, Decimus Clodius Albinus
(Albinus=Albus?) attempted to seize the throne but ended up as Caesar in alliance with another imperial contender, Septimius Severus. After Severus defeated two other rivals (Voldemort and... maybe Slytherin?), the now expendable Albinus was forced into another attempt at usurpation, an attempt that came to an end at the bloody battle of Lyon.
Aragog - "Arachnid" means spider. Gig is a giant. Put them together you get large spider ("ara"-arachnid, "gig"-large) and if Ara is used as Arachnid and gig it's aragig. But maybe it was changed to Aragog.
Argus - In Greek mythology, Argus was a monster that had a hundred eyes and was ever so watchful.
Arthur - Could represent King Arthur. The legend presents Arthur as a leader in ancient times who defeats the Saxons and other enemies. He thereby unites the people of Britain in peace and harmony.
Beauxbatons - French for 'beautiful wands'.
Draco - Draco is a constellation that looks like a dragon but is a snake. In Latin, Draco means "dragon."
Dumbledore - Means "Bumblebee" in Latin.
Durmstrang - German phrase meaning storm and stress.
Dursley - A town near J.K. Rowlings's birthplace.
Filch - To "steal."
Firenze - Italian name for the city of Florence.
Flitwick - A town in England.
Fleur Delacour - Means "Flower of the Court" in French and "Flower of the Heart" in Latin.
Fluffy - "Cerebrus" the three-headed dog was the guarder of the underworld in Greek mythology.
Gilderoy - A highwayman known for being handsome.
Goyle - Goyle's first name is Gregory. Greg Goyle, say it ten times fast and it's Gargoyle, a foul monstrous beast.
Gringotts - Ingot, means bar/gold. Gringotts is filled with Galleons.
Hedwig - A saint that lived in Germany in the 13th and 14th centuries.
Hagrid - Name and tale comes from Greek myth. The ancient Hagrid from the myth was the god of Jewels. This god was said to be the kindest of the gods, but Hades framed him for the death of Piraeus's -the killer of Medusa - son. Hagrid was banished from Olympus but Zeus allowed him to stay as the watcher of the animals. And, the word haggard means "wild-looking".
Hermes - The Greek Messenger.
Lockhart - Town in Australia near Wagga Wagga ("Compose a poem about my defeat of the Wagga Wagga Werewolf"?).
Lucius - Similar to Lucifer (the devil).
Ludo - "ludus" in Latin means "game" and the verb "ludo" in Latin means "to play" hence Ludo Bagman being the head of the Department of Magical Games and Sports in the ministry.
Lupin - Lunar means moon. Lupin means wolf-like. Canis Lupus is the scientific name for wolf.
Malfoy - "Mal foi" means "bad faith" in French. Malfoy has "mal" in it, meaning evil.
McGonagall - Means "bad poet" in Latin.
Minerva - In Roman Mythology was the Goddess of Wisdom. In Greek Mythology she was the Goddess of War. She gave strict punishments.
Mirror of Erised - Erised backwards is desire (as in "you'll see what you desire").
Moody - Not in a good mood.
Nagini - 'Naga' is female snake in Sanskrit.
Nicholas Flamel - Was a real alchemist, and supposedly DID create the Philosopher's Stone (not "Sorcerer’s"). The tale was that he had spent decades of his life trying to create the Philosopher's Stone, which could turn any metal in to gold and unlock the secrets to immortality, but could not figure it out.

One night, Nicholas Flamel had a dream in which an angel came to his bed, held out a book and said, these words, which were to remain in the memory of the hearer: "Look well at this book, Nicholas. At first you will understand nothing in it -- neither you nor any other man. But one day you will see in it that which no other man will be able to see." Surely that would contain the secrets to making the Philosopher's Stone!

A short while later while he was alone in his shop a man in desperate need of money appeared with a book to sell. He recognized it as the book that the angel in his dream had been holding and paid for it immediately, without bargaining.

The problem was that the book was written in part Hebrew and he couldn't read it. All of the Jews in France had recently been driven out of his country by persecution. He knew that there were still many Jews left in Spain, so he copied a small-portion of the book and headed out on his journey to find a translator. He searched for months and couldn't find one, and so started his journey home in discouragement. During the quest homeward, he stopped at an inn and was fortunate enough to be joined at his table by a French merchant who had contacts with someone who might be able to translate the book. The French merchant introduced Flamel to his friend, the Maestro Canches. When Nicholas told him that he had with him the book of Abraham the Jew the Maestro's eye's lit up and he explained that Abraham the Jew was a venerable master who was a great master and spent his whole life studying the mysteries of the Cabala. His book had disappeared, surfacing in some remote corner of the globe for moments and then disappearing again. Unfortunately, the pages that Nicholas had brought with him was not enough to unlock the secrets of the stone. The Maestro agreed to go back to Nicholas's home and translate the entire book.

Ironically, on the journey home the Maestro fell ill and passed away. Nicholas piously buried him at a nearby church and continued on. When he arrived home he found his wife, his shop and his books as he had left them. Though it took him years, the pages that the Maestro had translated had given Nicholas enough clues to translate the book himself.

Adherring strictly to the rules within the book of Abraham the Jew, he first turned a half-pound of mercury in to gold. As he was changing the metals, he changed himself.

From this point on he was rich. He built hospitals, low-income housing for the poor, and churches and lived out the rest of his days joyously.

After Nicholas had reached the age of 80, he went about planning his death. Not the means of the death itself but the details such as his coffin, tombstone (the one he ordered was very heavy), burial location, etc. He wanted his death to be as perfect as his life.

Shortly after he died, rumors that he had created the Elixir of Life spread. Any prowlers seeking the stone that could turn any metal in to gold soon were lurking nearby his house and shop searching for the metal.

The heat soon died down and rumors that Nicholas Flamel and his wife Pernelle was still alive were forgotten. Many, many years later, an archaeologist named Paul Lucas talked to a Turk that told him that Nicholas and his wife Pernelle were still alive. Paul did more research and then wrote and published a book that said that the Flamels' burials were nothing but clever shams, and that they were still alive. The publication of this book aroused many curious people. The people were so curious that they dug-up Nicholas's grave and opened the coffin. There was nothing there.