No real special meaning. Had it since I was young. At the time I was crazy about a game called Legend of Legaia and well Terra was a ra-seru of Noa. (On the main characters). I still like the game so I don't mind using this simple username for most things.

Oh the other part, the numbers do have a meaning. 517. 5-may 17-favorite number.

It's what comes in my head, and plus it's like a default name for most of my accounts.

it is a city in norway, though i have nothing to do with the city, i just think it sounds pretty cool