  We introduce the notion of p-adic equiangular lines and derive the first
fundamental relation between common angle, dimension of the space and the
number of lines. More precisely, we show that if $\{\tau_j\}_{j=1}^n$ is p-adic
$\gamma$-equiangular lines in $\mathbb{Q}^d_p$, then \begin{align*} (1)
\quad\quad \quad \quad |n|^2\leq |d|\max\{|n|, \gamma^2 \}. \end{align*}
  We call Inequality (1) as the p-adic van Lint-Seidel relative bound. We
believe that this complements fundamental van Lint-Seidel \textit{[Indag.
Math., 1966]} relative bound for equiangular lines in the p-adic case.
