en béton

made of concrete; rock-solid

→ en
phrase Rare #41,532
made of concrete; rock-solid Used literally for something made of concrete and figuratively for something very strong, reliable, or convincing.
FR: Elle a un alibi en béton.
EN: She has a rock-solid alibi.

Il a un alibi en béton.

He has a cast-iron alibi.

Les murs étaient en béton.

The walls were made of concrete.

— Fight Club (1999)

Ce mur est-il en béton ?

Is this wall made of concrete?

Mec, tu as un cœur en béton.

Dude, you have a heart of stone.

— Troupe d'Élite (2007)

Son alibi semblait être en béton.

His alibi seemed to be cast in stone.

Il nous faut une analyse positive en béton avant qu'on se lance.

We need a rock-solid positive analysis before we get started.

— Toni Erdmann (2016)

Logements sociaux, des cages en béton.

Social housing, concrete cages.