IPA: /faʊnˈdeɪʃənəli/
KK: /faʊnˈdeɪʃənəli/
In a way that relates to the basic or essential parts of something.
The principles were foundationally important to the development of the theory.
Foundationally → It is formed from "foundation" (from Old French *fundacion*, meaning the act of establishing or laying a base) and "-ally" (meaning in a manner relating to). The word "foundationally" means in a manner that relates to the basis or foundation of something.
Think of 'foundation' as the base of a building, and remember that 'foundationally' means acting in a way that relates to that base.