spine lettering; title on the spine of a book
Refers specifically to the text printed on the spine of a book, often the title and author.
I have a book whose spine lettering has worn off and become unreadable.
I searched for the book in the library relying only on the spine lettering.
Compound of 背 (se, 'back/spine') and 文字 (moji, 'letter/character'). The reading せもじ is a straightforward combination.