is $x^{100000000000}$ a “polynomial time”?

Question

per this post

$t = x^2$ means the problem is solvable in "Polynomial" time.

per this post

in the form

$$a_{n}x^{n}+a_{n-1}x^{n-1}+\dotsb +a_{2}x^{2}+a_{1}x+a_{0} { > \boldsymbol{=0}}$$

plug in $n=100000000000$ with $a_n=1$ and $a_k=0$ for all $k \neq n$

then we see that $x^{100000000000}$ is a polynomial

it doesn't matter if its 2, 3, or a billion, as long as the n is a finite number

in this context, does $t = x^{100000000000}$ still mean the problem is solvable in "Polynomial" time?