principial

As a noun terms

is .

As an adjective principial is

(obsolete) elementary.

In obsolete terms the difference between principal and principial

is that principal is an essential point or rule; a principle while principial is elementary.

As adjectives the difference between principal and principial

is that principal is primary; most important while principial is elementary.

As a noun principal

is the money originally invested or loaned, on which basis interest and returns are calculated.