As adverbs the difference between principally and chiefly
is that principally is in a primary manner; pertaining to the principal of a matter while chiefly is especially or primarily; above all.
As an adjective chiefly is
of, or relating to a chief.
principally
English
Adverb
(-)
In a primary manner; pertaining to the principal of a matter.
chiefly
English
Adverb
(
en adverb)
(focus) especially or primarily; above all
(focus) mainly or principally; almost entirely