Zoro lost to:
- Arlong
- Enel
- Rob Lucci
- Kuma
- Kizaru
- THE YETI COOL BROTHERS
- Kaido
Neither of those are actually a loss... I will explain why.
Arlong - from the start of the arc, Zoro was never in good condition, he was losing consciousness just from standing... Beaten up while already dead does not count as a loss, Arlong is not stronger than Zoro, Zoro simply wasnt in a condition to fight properly.
Enel - this is the same situation, by the time Zoro arrived at Enel he already had 2 big fights and was plenty injured and exhausted. Removing last 10% stamina that Zoro had left is not a loss for Zoro, however, I think he would have lost this one even in good condition.
Rob Lucci - being kicked away has never been a loss. Lucci stands no chance against Zoro.
Kuma - he never managed to land a clean hit on Zoro, they stopped the fight due to a deal. Idk where you see a loss in here...
Kizaru - cheap shot on already exhausted Zoro is a loss? It is getting ridiculous...
Yetis - cheap shots arent loses, Zoro was never bested by them...
Kaido - there is no loss here. Kaido never managed to land a hit on Zoro until Zoro exhausted himself and fell down on his own, mainly because of Hakai which is something that Kaido cannot pull off by himself. If you claim this a loss, it is due to 2vs1.
The only loss in here would be Enel if Zoro was in good condition because Enel was literally designed to be stopped only by his natural counter. Removing the last 5% HP from exhausted Zoro is not beating Zoro, he was never affected by those which you call a loss. Compare them to losing properly against Mihawk and you might get what I am talking about... Zoro is designed not to lose.