In Russian, according to Wikipedia, the longest Russian word is Тысячевосьмисотвосьмидесятидевятимикрометровый (46 words). The word means 1989-micrometer. However, according to some of my Russian friends, the longest Russian word is достопримечательности (21 words), the word means attractions.
The 45-letter word Pneumonoultramicroscopicsilicovolcanoconiosis is the longest word in English, I don't "know" what it means : ))). Accoring to Oxford dictionary, the word means an obscure term ostensibly referring to a lung disease caused by silica dust @@!!!
In my language, Vietnamese, the longest word is just only 7-letter word: Nghiêng, the word means oblique or slope.
So how about this in your language?

