Normally, I think of "Cardinal" as "Moving". Like, Aries is a Cardinal Fire sign. Imagine moving fire... it's lava coming for you and there is nothing you can do about it. There are three qualities: Cardinal ("moving"), Fixed ("not moving") and Mutable (or "faint"). Fixed water, or water that doesn't move, is ice (Scorpio). Mutable Earth, or Earth that ends is a precious gem or stone (Virgo).
If you mean Nathan Kress** then his birthday is November 18, 1992. That would make him a Scorpio.
There was/is a cardinal nearby
it is a math term
no
The Cardinal Bird is most often linked to Christmas. Indian legend has it that if you see a Cardinal flying towards the sun it is a sign of good fortune.
A cardinal is a senior ecclesiastical official, usually an ordained bishop, and ecclesiastical prince of the Catholic Church
Cardinal numbers - it's Spanish.
a number denoting quantity
Cardinal numbers - it's Spanish.
Chicago does not have a unique state bird. If you mean what is the Illinois state bird that would be the northern cardinal
Finding a cardinal's feather has no significance other that the pleasure of finding such a pretty thing. There is nothing supernatural involved.
Coincidence.