What is un bouquin? Well, it’s the colloquial word for un livre, a “book”. But what is its origin? It comes from the Netherlandish “boek”, which means “book”. It has been used in France since the 15th century. At that time, “boucquain” (former spelling) was used to name a book one would not care much about. Nowadays, the word is less pejorative, as we can say J’ai lu un bon bouquin, “I’ve read a good book”.
Related to bouquin is the word bouquinistes (second-hand booksellers). Maybe you have seen some of them along the Seine in Paris?