What is the longest word in English language that has 1 sllyable?

This is a bit of a trick question! There's no single "longest word" in English with just one syllable.

Here's why:

* Syllables are based on sound, not letters: A syllable is a unit of pronunciation with a single vowel sound.

* Words can have multiple letters representing a single sound: Think of words like "straight" or "through" - they have multiple letters, but only one vowel sound, making them one syllable.

So, to answer your question directly, there's no single word that's definitively the "longest" one-syllable word.

Let me know if you'd like to explore some of the longest one-syllable words, or if you want to delve into different word length and syllable combinations!