Is RESTY a Wordle Word?

Yes. RESTY is a valid Wordle word.

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

What does RESTY mean?

Restive, resistant to control.“In vaine the Pagan bannes, and sweares, and rayles, / And backe with both his hands unto him hayles / The resty raynes […]”
Disposed to rest; inactive, lazy.“[…] Come; our stomachs / Will make what’s homely savoury: weariness / Can snore upon the flint, when resty sloth / Finds the down pillow hard.”

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

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

Hard-mode trap: 7 valid words fit the pattern _ESTY. 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.