A return or reversal; an action of giving something back or replying/retorting (e.g., a comeback).
彼の返しの早さに、司会もたじろいだ。
The host was taken aback by how quick his retorts were.
問題の返しがうまくいかず、計画は元に戻った。
The reversal of the issue didn't go well, and the plan reverted to its original state.
A return gift; a present given in return for a favor or a gift received.
結婚祝いをもらったので、お返し（返し）を送った。
I received a wedding gift, so I sent a return gift.
お歳暮の返しは手頃な価格の品が一般的だ。
Return gifts for year-end presents are generally items of moderate price.
お世話になった方には、何か返しをしたいと思っている。
I want to give something back to those who helped me.
The barb on a fishhook — a small backward-facing projection that helps prevent the fish from slipping off.
釣り針の返しが大きいと魚が逃げにくいが、外すのが大変だ。
If the barb on the hook is large, it's harder for the fish to escape, but it's difficult to remove.
海釣りでは返しを潰して使うこともある。
In sea fishing, people sometimes flatten the barb before use.
A seasoning blend (often a base for soups or dipping sauces) made from soy sauce, sugar, mirin, etc.; a concentrated sauce base used for noodle broths.
うどん屋では朝に大量の返しを仕込む。
Udon shops prepare a large batch of sauce base (kaeshi) in the morning.
だしと返しを合わせてつゆを作る。
Combine dashi and kaeshi to make the soup broth.