Principal adjectives are listed in this post. Each word below can often be found in front of the noun principal in the same sentence. This reference page can help answer the question what are some adjectives commonly used for describing PRINCIPAL.
american, assistant, associate, basic, current, effective, elementary
entire, female, first, foreign, former, founding, fundamental
general, good, late, le, male, monthly, more
most, new, old, original, other, outstanding, own
present, previous, real, same, school, second, successful
such, third, total, undisclosed, unpaid, whole
Hope this word list had the adjective used with principal you were looking for. Additional describing words / adjectives that describe / adjectives of various nouns can be found in the other pages on this website.