  We investigate a single field model in the context of the constant-roll
inflation in which inflaton moves down to the minimum point of the potential
with a constant rate of rolling. We use a quintessential inflationary model
obtained by a Lorentzian function which is dependent on the number of e-folds.
We present the inflationary analysis for the model and find the observational
constraints on the parameters space using the observations of CMB anisotropies
\textit{i.e.} the Planck and Keck/array datasets. We find the observationally
acceptable values of the Width of the Lorentzian function as
$0.3<\Gamma\leq0.5$ at the $68\%$ CL and $\Gamma\leq0.3$ at the $95\%$ CL when
$\xi=120$, $|\beta|=0.02$ and $N=60$. Also, we acquire the observationally
favoured values of the amplitude of the Lorentzian function as $400<\xi\leq600$
at the $68\%$ CL and $\xi\leq400$ at the $95\%$ CL when $\Gamma=0.1$,
$|\beta|=0.02$ and $N=60$. Moreover, we study the model from the Weak Gravity
Conjecture approach using the swampland criteria.
