The Longest One-Syllable Word

A one-syllable word is a type of word that only has one syllable. Syllables are units of sound in a word that contain a vowel sound. A single syllable can be short or long, but it always contains just one vowel sound.

The Answer:

According to the Oxford English Dictionary and other linguistic sources, the longest one-syllable word is stewardship, however this word has 2 syllables if you break down the pronunciation: ste-wa-rd-ship.

After verifying multiple sources, it appears that strengths and strengthen are also often cited as having two syllables when pronounced correctly: str-en-gths and str-en-then respectively.

But there’s a word that is generally accepted by linguists as the longest single-syllable word in the English language:

Rhythm

Yes, the word Rhythm indeed has only one syllable when pronounced correctly: Rithm.