Invented brand name, suitable for a range of applications.
The word "killy" contains only five letters and just two syllables. Two-syllable names are very rare and highly valued. Two syllable names are used by established brands like YouTube, Walmart and Hilton.
Killy.com is a .com domain. Dot com domains are the most valued domain extension in the world, used by famous websites like google.com. When you own a .com, it is much easier to rank for your own name in search engines.