What is the longest noun in English?

There are a few contenders for the longest noun in the English language, and it depends on how you define "longest" and what you consider a "noun."

Here are a few possibilities:

* Floccinaucinihilipilification (29 letters): This word refers to the act of estimating something as worthless.

* Antidisestablishmentarianism (28 letters): This word refers to opposition to the separation of church and state.

* Pseudopseudohypoparathyroidism (30 letters): This is a medical term for a genetic disorder that affects bone development.

However, if you're looking for a single-word noun with the most letters, "pneumonoultramicroscopicsilicovolcanoconiosis" (45 letters) takes the crown. It refers to a lung disease caused by inhaling very fine silica dust.

It's worth noting that some of these words are considered "portmanteau" words, which are formed by blending two or more words. Ultimately, the "longest noun" can be a bit of a subjective debate!