IPA: /ˈkruːʃəli/
KK: /ˈkruːʃəli/
In a way that is very important or essential.
The decision will crucially affect the outcome of the project.
Crucially → It is formed from "crucial" (from Latin "crucialis", meaning pertaining to a cross or decisive) and the suffix "-ly" (meaning in a manner of). The word "crucially" means in a manner that is decisive or of great importance.
Think of something that is 'decisive' ('crucial') and how it is done 'in a manner' ('-ly'). This helps you remember that 'crucially' refers to something done in a very important way.