佚書[issho] lost book
佚する[issuru] to lose (a chance)
佚楽[itsuraku] pleasure
安佚[anitsu] (idle) ease

放佚[houitsu] self-indulgence
散佚[sanitsu] being scattered and ultimately lost
淫佚[initsu] debauchery

愛書[aisho] great love of books
愛読書[aidokusho] favourite book
悪書[akusho] harmful book
案内書[annaisho] guidebook
移動図書館[idoutoshokan] mobile library

遺言書[yuigonsho] testament
遺書[isho] note left by dead person
医書[isho] medical book
一つ書き[hitotsugaki] an item
一書[issho] one letter