Definition:Monic Polynomial

Definition
Let $\left({R, +, \circ}\right)$ be a ring with unity whose unity is $1_R$.

Let $\left({S, +, \circ}\right)$ be a subring of $R$.

Let $\displaystyle f = \sum_{k \mathop = 0}^n a_k \circ x^k$ be a polynomial in $x$ over $S$.

Then $f$ is a monic polynomual iff its leading coefficient $a_n$ is $1_R$.