This is the 18053rd most frequent Russian word.
французском
"Французском" means "French" (prepositional case, singular, masculine form).
The word 'французском' is used as an adjective describing 'языке' (language), indicating the characteristic of the language as French.
Он знает несколько слов на французском языке.
He knows a few words in French.
The word 'французском' functions as a noun within the phrase 'на французском', referring to the French language.
На французском она звучит особенно красиво.
In French, it sounds especially beautiful.
Here, 'французском' again serves as the descriptive term for the language attribute of the object of reading, emphasizing the language of the text.