Boniment

Faiseur de boniment (pop.) = A cheap-jack, clap-trap speaker.

[Bonir = to talk like clowns at a fair.]

Bonjour

C’est simple comme bonjour = It is as easy as kiss your hand.

Bonnet

*C’est bonnet blanc et blanc bonnet = It is six of one and half-a-dozen of the other.

C’est un des gros bonnets (or, légumes) de l’endroit = He is one of the bigwigs of the place.

Il a la tête près du bonnet = He is quick-tempered, easily ruffled.

Il a mis son bonnet de travers = He is in a bad temper; He got out of bed the wrong side.