The planet Venus.
- ‘This is a tautology since Hesperus and Phosphorus are both the planet Venus - the two expressions thus have the same extension.’
- ‘An old Greek poet whispered in her mind: Hesperus, evening star, golden lamp of the daughter of the foam!’
- ‘It was a discovery about the heavens that Hesperus is Phosphorus; it was a new piece of knowledge that the Ancients gained.’
- ‘Against this claim, it may be urged that one can perfectly well imagine a possible world in which astronomers discover that Hesperus and Phosphorus are two distinct planets.’
Latin, from Greek hesperos western (as a noun) the evening star related to Latin vesper evening (star) (see vesper).