Brilliant business name based on the word "define".
Definely has eight letters and three syllables. Successful brands using three syllable names include Grammarly, Microsoft and Mastercard.
Definely.com is a .com domain. Dot com domains are the most valued domain extension in the world, famously used by websites like facebook.com. Once you own a .com, it will be much easier to rank for your own name in Google.