Is RUNES a Wordle Word?

Yes. RUNES 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 RUNES mean?

A letter, or character, belonging to the written language of various ancient Germanic peoples, especially the Scandinavians and the Anglo-Saxons.
A Finnish or Scandinavian epic poem, or a division of one, especially a division of the Kalevala.
A letter or mark used as mystical or magic symbol.

3 more noun definitions

A verse or song, especially one with mystical or mysterious overtones; a spell or an incantation.
A roun (secret or mystery).
In the Go programming language, a Unicode code point.

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

Starter word rating: GoodIn the top 7% of all valid Wordle words for testing common letters.
Vowels: U, E
Unique letters: 5 of 5
Common letters: R, E

Hard-mode trap: 6 valid words fit the pattern RU_ES. If you reach it, you may need several guesses to find the last letter.

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.