Origin: Latin suffix -ous
Perfidious has 2 different meanings across 1 category:
tending to betray; especially having a treacherous character as attributed to the Carthaginians by the Romans
"Punic faith"
"the perfidious Judas"
"the fiercest and most treacherous of foes"
"treacherous intrigues"
Of, pertaining to, or representing perfidy; disloyal to what should command one's fidelity or allegiance.