removeChild

<ul class="list">
    <li class="item">1st</li>
    <li class="item">2nd</li>
    <li class="item">3rd</li>
</ul>

const list = document.querySelector(".list");
const items = document.querySelectorAll(".item");

for ( let i = 0; i < items.length; i++ ) {
    list.removeChild(items[i]);
}