What is the longest one syllable word in English language?

This is a bit of a trick question! There are a few contenders, but it depends on how you define "one syllable" and "word":

* "Strengths" is often cited as the longest one-syllable word, but technically it has two syllables ("strengths").

* "Scourge" is a very strong contender, often pronounced as one syllable.

* "Through" is another word with a single sound, although some dialects might pronounce it with a slight "oo" sound.

Ultimately, the answer depends on how you're defining "syllable" and what pronunciation you're using.