\begin{definition}[Definition:Repunit]
Let $b \in \Z_{>1}$ be an integer greater than $1$.
Let a (positive) integer $n$, greater than $b$ be expressed in base $b$.
$n$ is a '''repunit base $b$''' {{iff}} $n$ is a repdigit number base $b$ whose digits are $1$.
That is, $n$ is a '''repunit base $b$''' {{iff}} all of the digits of $n$ are $1$.
When $b$ is the usual base $10$, $n$ is merely referred to as a '''repunit'''.
\end{definition}