Invented brand name, suitable for a range of applications.
The word "killy" contains only five letters and just two syllables. Two-syllable names are exceptionally rare and exceptionally valuable. Leading companies using two syllable names include Ikea, Delta and Boeing.
Killy.com is a dot-com domain. Dot com domains are the most desirable top-level-domain in the world, famously used by websites like youtube.com. A dot-com is the first thing people think of when they think of a website.