Principally
Pronunciation : Prin"ci*pal*ly
Part of Speech : adv.
Definition : Defn: In a principal manner; primarily; above all; chiefly; mainly.
Source : Webster's Unabridged Dictionary, 1913
Merriam-Webster's Everyday Language Reference Set: Includes: The Merriam-Webster Dictionary, The Merriam-Webster Thesaurus, and The Merriam-Webster Vocabulary Builder