Each thing, all, and each item are all synonyms for everything. Nothing and none are antonyms of everything. And here are 17 another word for everything.
All, each item, each thing, every article, every single thing, the aggregate, the entirety, the full monty, the lot, the total, the whole (kit and) caboodle, the whole ball of wax, the whole lot, the whole shebang, the whole shooting match, and the whole nine yards are all synonyms for everything.
Everything synonym page has a variety of synonyms that differ in length. 1 synonym with 3, 6, 9, 15, 16, 17, 21, and 22 letters and 2 synonyms with 8, and 11 letters. 3 synonyms with 12 letters. For a total of 15 another word for everything.
He found nothing in the box.
There’s nothing more to discuss here.
She said nothing during the meeting.
Nothing could change his determined mind.