wordbook UK /ˈwɜːdˌbʊk/US /ˈwɝdˌbʊk/ noun4 •A reference book that lists words. •A dictionary. •A reference book that focuses mainly on lexicon (vocabulary), spelling, and (sometimes) syllabication, but with little to no information about definitions, synonyms, history, or usage. •The libretto of an opera. formswordbooks