Rond de tranche in French butchery refers to a specific cut of beef from the round primal, particularly the "eye of round". The term "tranche" generally refers to the rear part of the cow, or the round in English. The rond de tranche or "eye of round" is a lean, boneless cut of beef that's found in the rear leg of the cow.
It's shaped like a tenderloin but tends to be much tougher since it comes from a part of the cow that sees a lot of movement. Due to its lean nature and lack of marbling, the rond de tranche is best when cooked with slow, moist cooking methods, like braising, that help to tenderize the meat.