Invented brand name, suitable for a range of applications.
The name "killy" has only five characters and just two syllables. Two-syllable names are very rare and highly valuable. Established brands using two syllable names include Disney, Gucci and FedEx.
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 secured, a dot com all but guarantees no-one else can outrank you for your own name in the long run.