fall flat

US /fɔl flæt/
UK /fɔl flæt/
"fall flat" picture
1.

tomber à plat, échouer

fail to produce an intended effect; be unsuccessful

:
His jokes often fall flat with the audience.
Ses blagues tombent souvent à plat auprès du public.
The marketing campaign seemed to fall flat, as sales did not improve.
La campagne de marketing a semblé tomber à plat, car les ventes ne se sont pas améliorées.