verb/nə pa ka.se tʁwa pat a œ̃ ka.naʁ/
to be nothing to write home about (to be mediocre; to be nothing out of the ordinary; to be nothing special)
Literally, “to not break three feet of a duck”; because ducks are bipeds, it would be quite out of the ordinary to break a third foot. Another explanation is that it derives from the similar-sounding cagnard (“crooked horse”), in allusion to a horse rider: only a daring rider would risk pushing his horse to the point where it breaks one or more legs.