  In this work, a new fast-roll (FR) mechanism to generate primordial black
holes (PBHs) and their coeval gravitational waves (GWs) in generalized
non-canonical natural inflation is introduced. In this model, choosing a
suitable function for non-canonical mass scale parameter $M(\phi)$ gives rise
to produce a cliff-like region in field evolution path. When inflaton rolls
down the steep cliff, its kinetic energy during the FR stage is amplified in
comparison with slow-roll (SR) stage. Hence, seeds of PBHs production are born
in this transient FR stage. Depending on the position of the cliff, appropriate
cases of PBHs for explaining total dark matter (DM), microlensing effects,
LIGO-VIRGO events and NANOGrav 15 year data can be formed. The density spectrum
of GWs related to one case of the model lies in the NANOGrav 15 year domain and
behaves like $\Omega_{\rm GW_0}\sim f^{5-\gamma}$. The spectral index
$\gamma=3.42$ for this case satisfies the NANOGrav 15 year constraint.
Moreover, regarding reheating considerations, it is demonstrated that PBHs are
born in radiation-dominated (RD) era. Furthermore, viability of the model in
light of theoretical swampland criteria and observational constraints on cosmic
microwave background (CMB) scales are illustrated.
