'bibliothecal' originates from the Greek word 'bibliothēkē', where 'biblio-' meant 'book' and '-thēkē' meant 'receptacle'.

'bibliothēkē' transformed into the Latin word 'bibliotheca', and eventually became the modern English word 'bibliothecal'.

Initially, it meant 'a place for books', but over time it evolved into its current meaning of 'relating to a library'.