This is the 813th most frequent French word.
allemand
"Allemand" means "German" in English.
Here, 'allemand' refers to the German language.
Je parle allemand couramment.
I speak German fluently.
Here, 'allemand' describes the nationality of the professor, indicating he is from Germany.
Il est un professeur allemand.
He is a German teacher.
In this case, 'allemand' is used as an adjective describing the noun 'livre' to mean that the book is German.