The host read-only property of the ShadowRoot returns a reference to the DOM element the ShadowRoot is attached to.
A DOM Element.
const customElem = document.querySelector("my-shadow-dom-element");
const shadow = customElem.shadowRoot;
// …
// return the original host element some time later
const hostElem = shadow.host;part and exportparts HTML attributes<template> and <slot> HTML elements:host, :host(), and :host-context() CSS pseudo-classes::part and ::slotted CSS pseudo-elements