What is the longest word in dictionary that confusing?

There's no single "longest word in the dictionary" that is universally agreed upon, and the idea of a "confusing" word is subjective. Here's why:

* Dictionaries vary: Different dictionaries have different word lists and different criteria for inclusion.

* Technical terms: Some dictionaries include highly technical terms, like "pneumonoultramicroscopicsilicovolcanoconiosis" (a lung disease), which are incredibly long but not commonly used.

* Proper nouns: Some dictionaries include extremely long place names or names of compounds, which are technically words, but not words you'd typically use in conversation.

That said, here are some contenders for "longest confusing words," depending on your definition:

* "Pneumonoultramicroscopicsilicovolcanoconiosis" is long and technical, but its meaning can be deciphered if you know the root words.

* "Floccinaucinihilipilification" is another long word, but its meaning ("the act of estimating something as worthless") is more common than the word itself.

* "Antidisestablishmentarianism" is a long and tricky word that refers to opposition to the separation of church and state.

Ultimately, the "most confusing" word depends on your personal experience and understanding of English.