Is PITHS a Wordle Word?

Yes. PITHS 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 PITHS mean?

To extract the pith from (a plant stem or tree).
To kill (especially cattle or laboratory animals) by cutting or piercing the spinal cord.

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

Starter word rating: WeakIn the top 57% of all valid Wordle words for testing common letters.
Vowels: I
Unique letters: 5 of 5
Common letters: I, T

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.