adjective/a kɥi.a/
silenced, nonplussed, speechless, tongue-tied, dumbfounded
“réduire quelqu'un à quia, mettre quelqu'un à quia” — to reduce to silence, to silence, to hush up
From Latin quia (“because”); when one is out of arguments, the only line of argumentation left is saying “because [I say so]”.