The Collaborative International Dictionary
Principial
Principial \Prin*cip"i*al\, a.
Elementary. [Obs.]
--Bacon.
Wiktionary
principial
a. (context obsolete English) elementary
Usage examples of "principial".
I have already given examples of this very general figure, which consists in admitting the accidental evil of a class-bound institution the better to conceal its principial evil.