A Google search to try to solve Meg's query about the longest word of just one syllable [why is monosyllabic such a long word?] led me to this page full of fascinating little facts about words. Here are just a couple of them:

Sestettes is a word in which each of its letters occurs three times.

Subbookkeeper is the only English word with four pairs of double letters in a row.

The longest words that can be typed using only the top row of a typewriter keyboard are ten letters long. One of these words is... typewriter.
And, related to Meg's query:

Strengths, at nine letters long, is not only just one syllable, but is also the longest English word containing just one vowel.