Invented brand name, suitable for a range of applications.
Killy has only five characters and only two syllables. Two syllable names make popular global brands. Successful brands using two syllable names include Boeing, Pocket and Sony.
Killy.com is a .com domain. Dot com domains are the most valuable top-level-domain in the world, used by famous websites like youtube.com. When most people think of a website, they think of a .com.