Is LONGS a Wordle Word?

Yes. LONGS 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 LONGS mean?

A long vowel.
A long syllable.
A note formerly used in music, one half the length of a large, twice that of a breve.

4 more noun definitions

A long integer variable, twice the size of an int, two or four times the size of a short, and half of a long long.
An entity with a long position in an asset.“Every uptick made the longs cheer.”
A long-term investment.
The long summer vacation at the English universities.

To await, aspire, desire greatly (something to occur or to be true)“She longed for him to come back.”

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

Starter word rating: WeakIn the top 48% of all valid Wordle words for testing common letters.
Vowels: O
Unique letters: 5 of 5
Common letters: L, O

Hard-mode trap: 11 valid words fit the pattern _ONGS. 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.