fundamentally — serving as, or being an essential part of, a foundation or basis; basic; underlying: fundamental principles; the fundamental structure.
incidentally — apart or aside from the main subject of attention, discussion, etc.; by the way; parenthetically.
incrementally — increasing or adding on, especially in a regular series: small, incremental tax hikes.
monumentally — resembling a monument; massive or imposing.
Four-or-more syllable rhymes
coincidentally — You use coincidentally when you want to draw attention to a coincidence.
developmentally — the act or process of developing; growth; progress: child development; economic development.