What is the longest word in Spanish language?

There's no single definitive "longest word" in Spanish, as it depends on how you define "word".

Here are a couple of possibilities, each with a caveat:

* "Electroencefalografista" (electroencephalographer) is often cited as the longest word, but it's debatable whether it's a true word or a technical term.

* "Antidisestablishmentarianism" is also a contender, though it's an English word that has entered Spanish usage. It's very long and technically used in Spanish, but not considered a common word.

Instead of focusing on "longest", here are some interesting aspects of Spanish vocabulary:

* Compounding: Spanish loves to create long words by combining existing words. This makes for some complex and descriptively powerful terms.

* Regional variation: Spanish spoken in different countries has its own unique words and phrases.

* Scientific and technical terms: These are often long and complex, reflecting the specialized nature of the language used.

Ultimately, the "longest word" in Spanish is more of a fun linguistic curiosity than a definitive answer.