Entry 2 senses · 2 variants Webster, 1913 Vesper /(vĕs"pẽr)/ · Ves·per · IPA /ˈvɛspɚ/ n. a. 01 n. The evening star; Hesper; Venus, when seen after sunset; hence, the evening. 1. The evening star; Hesper; Venus, when seen after sunset; hence, the evening. 02 a. Of or pertaining to the evening, or to the service of vespers; as, a vesper hymn; vesper bells. 1. Of or pertaining to the evening, or to the service of vespers; as, a vesper hymn; vesper bells. Phrases & compounds Vesper sparrow — the grass finch. See under Grass.