Emily Dickinson Lexicon

VES'PER, n. [L. This word and Hesperus are probably of one origin, and both from the root of west.]

1. The evening star; Venus; also, the evening.
2. Vespers, in the plural, the evening song or evening service in the Romish church. Sicilian vespers, the era of the general massacre of the French in Sicily, on Easter evening, 1282, at the toll of the bell for vespers.