This is the 7863rd most frequent French word.
siegenthaler
"Siegenthaler" is not a French word; it is a German surname.
Here, 'Siegenthaler' is used as a proper noun, likely referring to an author.
Le livre écrit par Siegenthaler est très apprécié.
The book written by Siegenthaler is highly appreciated.
In this sentence, 'Siegenthaler' is used as the surname of a person, indicating their occupation or field of expertise.
Siegenthaler travaille dans la recherche en biotechnologie.
Siegenthaler works in biotechnology research.
Here, 'Siegenthaler' is used to mention an individual's name encountered at a social event.