noun
cassette book
A book published on audio cassette, popular before digital audiobooks. Now largely historical.
図書館でカセットブックを借りて、車の中で聞いた。
I borrowed a cassette book from the library and listened to it in the car.
Variant with interpunct; less common in running text.
Modern digital audiobook; カセットブック specifically refers to the older cassette tape format.
Wasei-eigo from English 'cassette' + 'book'.