Literal Translation
Mute/silent as a carp
Actual Meaning
To be completely silent (in a variety of contexts including silent as the grave)
Etymology
Fish don’t have vocal cords; they don’t speak or make sounds with their mouths. It is therefore not surprising that this aquatic animal was used in an expression evoking silence. As a reminder, the famous Commander Cousteau considered the bottom of the ocean to be the world of silence. But why was a carp chosen and not another species of fish? In his Dictionnaire des expressions et locutions (Dictionary of Expressions and Phrases), linguist Alain Rey mentions two possibilities based on:
(1) The anatomy of cyprinids. This first hypothesis is based on the postulate established in 1690 by French lexicographer Antoine Furetière that carp cannot speak because they have no tongue.
(2) The behaviour of the animal. The second theory is based on the fish’s habit of frequently sticking its head out of the water with its mouth wide open, but without uttering a word, just like a mute person. This latter behaviour gave rise to the expression ‘to yawn like a carp’.
Found in the works of Rabelais, the phrase has existed since 1612 in its original form, ‘silent as a fish’. Two and a half centuries later, Jules Verne used the expression again: ‘With that, silent as fish. Marcel, wanting to strike up a conversation with them for diplomatic purposes, received only fierce glances in response’. As for George Sand, she uses a variation – ‘silent as a tench’ – in her work Les Maîtres Sonneurs. Over the decades, many authors have adopted the expression in its current form.
Bonus: muet comme une tombe also exists