Is MISTS a Wordle Word?

Yes. MISTS 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 MISTS mean?

/mɪsts/

Water or other liquid finely suspended in air.“It was difficult to see through the morning mist.”
A layer of fine droplets or particles.“There was an oily mist on the lens.”
Anything that dims, darkens, or hinders vision.

To form mist.“It's misting this morning.”
To spray fine droplets on, particularly of water.“I mist my tropical plants every morning.”
To cover with a mist.“The lens was misted.”

1 more verb definition

(of the eyes) To be covered by tears.“My eyes misted when I remembered what had happened.”

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

Starter word rating: WeakIn the top 82% of all valid Wordle words for testing common letters.
Vowels: I
Unique letters: 4 of 5Repeats S
Common letters: I, T

Hard-mode trap: 10 valid words fit the pattern _ISTS. 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.