conviction

/kɔ̃.vik.sjɔ̃/
1.
nounfeminine

belief

firm belief

certainty

Sa conviction qu'il faut agir maintenant est inébranlable.

His conviction that action is needed now is unshakeable.

Synonyms:certitude, croyance, assurance, foi
2.
nounfeminine

persuasiveness

sincerity (in delivery)

force of conviction / convincingness

Elle a répondu sans conviction — on sentait qu'elle n'y croyait pas.

She answered without conviction — you could tell she didn't believe it.

Synonyms:persuasion, force, sincérité, crédibilité