Invented brand name, suitable for a range of applications.
Killy has only five letters and only two syllables. Two-syllable names are highly rare and highly prestigious. Successful brands using two syllable names include Boeing, Disney and Gillette.
Killy.com is a dot-com domain. Dot com domains are the most sought after domain extension in the world, famously used by websites like google.com. Once you own a dot-com, it will be much easier to rank for your own name in Google.