'Evening primrose' definitions:

Definition of 'evening primrose'

noun

Any of several plants of the family Onagraceae

From: GCIDE

Primrose \Prim"rose`\, n. [OE. primerole, F. primerole, a derivative fr. LL. primula, from L. primus first. See Prime, a.] (Bot.) (a) An early flowering plant of the genus Primula ({Primula vulgaris}) closely allied to the cowslip. There are several varieties, as the white-, the red-, the yellow-flowered, etc. Formerly called also primerole, primerolles. (b) Any plant of the genus Primula. [1913 Webster]
Evening primrose, an erect biennial herb ({Enothera biennis}), with yellow vespertine flowers, common in the United States. The name is sometimes extended to other species of the same genus.
Primrose peerless, the two-flowered Narcissus ({Narcissus biflorus}). [Obs.] [1913 Webster]

From: GCIDE

Evening \E"ven*ing\, n. [AS. [=ae]fnung. See even, n., and cf. Eve.]
1. The latter part and close of the day, and the beginning of darkness or night; properly, the decline of the day, or of the sun. [1913 Webster]
In the ascending scale Of heaven, the stars that usher evening rose. --Milton. [1913 Webster]
Note: Sometimes, especially in the Southern parts of the United States, the afternoon is called evening. --Bartlett. [1913 Webster]
2. The latter portion, as of life; the declining period, as of strength or glory. [1913 Webster]
Note: Sometimes used adjectively; as, evening gun. "Evening Prayer." --Shak. [1913 Webster]
Evening flower (Bot.), a genus of iridaceous plants (Hesperantha) from the Cape of Good Hope, with sword-shaped leaves, and sweet-scented flowers which expand in the evening.
Evening grosbeak (Zo["o]l.), an American singing bird (Coccothraustes vespertina) having a very large bill. Its color is olivaceous, with the crown, wings, and tail black, and the under tail coverts yellow. So called because it sings in the evening.
Evening primrose. See under Primrose.
The evening star, the bright star of early evening in the western sky, soon passing below the horizon; specifically, the planet Venus; -- called also Vesper and Hesperus. During portions of the year, Mars, Jupiter, and Saturn are also evening stars. See Morning Star. [1913 Webster]