One of the mysteries of the English language finally explained.
With reference to an act of translation, a sermon, or other activity based on a text: extemporaneously, without preparation or recourse to reference materials.
Late 17th century. From post-classical Latin ad aperturam libri from classical Latin ad at + apertūram, accusative of apertūra + librī, genitive of liber book.
ad aperturam libri/ad ˌapəˈtʃʊərəm ˌlɪbri/
In this article we explore how to impress employers with a spot-on CV.