～きる
～きる · ～kiru · JLPT N2 · noun
to carry through
✂️ From 切る, to cut: you cut all the way through, so the action is finished
Add it to a verb stem to mean doing something completely: 食べきる is to eat it all up, 使いきる is to use it all up, and 言いきる is to say it outright. Just as a cut goes through to the other side, the action goes all the way to the end.