at length, for a long time
Je dois y réfléchir plus longuement.
I need to think about it at greater length.
— Carnets de voyage (2004)
Ma mère s'assit à l'école ce jour-là, longuement.
My mother sat at school for a long time that day.
— The Road Home (1999)
Nous discutâmes longuement du problème.
We discussed the problem at length.
Je l’avais emmené déjeuner et l’avais longuement interrogé sur Lore-West.
I’d taken him out to lunch and questioned him at length about Lore-West.
Alors, je me suis longuement regardé dans la glace.
So, I looked at myself in the mirror for a long time.
— Bullet Train (2022)
Alors, il va te falloir discuter longuement avec lui.
So, you're going to have to have a long discussion with him.
Nous avons parlé longuement du sujet.
We talked about this at length.
Ils marchèrent longuement sans boire d'eau.
They walked for a long time without drinking any water.