to a great degree (adverb) principally: mainly
Sinonime: above all,
basically, before anything else, cardinally, chiefly, dominantly,
eminently,
especially,
essentially, first and foremost, first of all, for the most part,
fundamentally,
generally, importantly, in the first place, in the main,
largely, materially,
mostly,
notably,
particularly, peculiarly, predominantly, preeminently, prevailingly, prevalently,
primarily,
substantially, superlatively, supremely, to a great degree, universally, vitally
Antonime: secondarily, trivially