Is YOYOS a Wordle Word?

Yes. YOYOS is a valid Wordle word.

It is not on the Wordle answer list, so it is unlikely to be a daily answer.

Plurals ending in S are almost never chosen as Wordle answers.

What does YOYOS mean?

A toy consisting of a spheroidal or cylindrical spindle having a circular groove in which string is wound; it is used by holding the string in the fingers and reeling the spindle up and down by movements of the wrist.“I bought a yo-yo from the toy store yesterday.”
A volatile market that moves up and down.
Someone who vacillates.

2 more noun definitions

A cloth rosette formed by gathering the outside edge of a circle of fabric in toward the centre using a running stitch.
A foolish, annoying or incompetent person.“It is hard to watch the management for very long and not conclude that the place is run by a bunch of yo-yos.”

Definition from Wiktionary, available under the CC BY-SA license.

Starter word rating: WeakIn the top 97% of all valid Wordle words for testing common letters.
Vowels: O
Unique letters: 3 of 5Repeats Y, O
Common letters: O

Letter ratings use how often each letter appears in Wordle answers.

Tap its tiles to the colours Wordle showed, and the Wordle Solver lists every word that still fits, with the best next guess.