IPA: /kəˈlɒsəli/
KK: /kəˈlɑsəli/
In a very large or great way; extremely.
The project was colossally successful, exceeding all expectations.
Colossally → It is formed from "colossal" (from Latin *colossalis*, meaning gigantic or enormous) and the suffix "-ly" (meaning in a manner of). The word "colossally" means in a manner that is gigantic or extremely large.
Think of something that is 'gigantic' ('colossal') and remember that 'colossally' means in a gigantic manner.
No commonly confused words.