Late 15th century: from Old French vespres 'evensong', from Latin vesperas (accusative plural), on the pattern of matutinas 'matins'.

• west from Old English:

  All of the words for compass points are Old English. West can be traced back to an ancient root that also produced Latin vesper ‘evening’, also the source of the church service vespers (Late Middle English), the connection being that the sun sets in the west. Go west, meaning ‘be killed’, comes from the idea of the sun setting in the west at the end of the day, and became common during the First World War. The expression is also used more generally in the sense ‘be lost or broken’, and this is the meaning found in the American equivalent go south. The choice of a different compass point is possibly connected with the idea of something being on a downward trend, or perhaps go west sounded too positive, given the hopeful promise of the American West represented in the exhortation ‘Go west, young man! Go west!’, recorded from 1851. The lawless western frontier of the USA during the period when settlers were migrating from the inhabited east was known as the Wild West from the 1840s, and was the setting for Westerns featuring cowboys, Indians, and cattle rustlers from about 1910. See also twain