unfounded

The allegations they made were unfounded.

Les accusations qu’ils ont portées étaient infondées.

These accusations are unfounded.

Ces accusations sont infondées.

But that was totally unfounded.

Mais c'était totalement infondé.

— Toni Erdmann (2016)

That's a completely unfounded rumor.

C'est une rumeur complètement infondée.

The rumors are unfounded.

Ces rumeurs sont infondées.

Your criticism is unfounded.

Votre critique est infondée.

Your argument is unfounded.

Votre argument est infondé.