Primarily

наречие 1) первоначально Синоним(ы): firstly, originally 2) в основном, главным образом Синоним(ы): chiefly, principally, essentially, pre-eminently

Большой англо-русский словарь

Primarily

adverb 1. for the most part; chiefly Example: has now become primarily a residential town — S. P. B. Mais 2. in the first place; originally

Энциклопедический словарь Мерриама-Вебстера