Narcissus is the botanic name for a genus of mainly hardy, mostly spring-flowering, bulbs in the Amaryllis family native to Europe, North Africa, and Asia. There are also several Narcissus species that bloom in the autumn. Though Hortus Third [1] cites 26 wild species, Daffodils for North American Gardens[2] cites between 50 and 100 excluding species variants and wild hybrids. Through taxonomic and genetic research, it is speculated that over time this number will likely continue to be refined.[3] Daffodil is a common English name, sometimes used now for all varieties, and is the chief common name of horticultural prevalence used by the American Daffodil Society.[4] The range of forms in cultivation has been heavily modified and extended, with new variations available from specialists almost every year.

The name Narcissus is derived from that of the youth of Greek mythology called Narcissus, who, in at least one of many variations of the tale, became so obsessed with his own reflection as he kneeled and gazed into a pool of water that he fell into the water and drowned. The legend continues that the Narcissus plant first sprang from where he died.

There are several plurals in common use: "Narcissuses", and "Narcissus". This last is common in American English, and is the form preferred by the American Daffodil Society, but it is very rare in British usage. The American Webster's Third New International Dictionary gives plurals in the order "Narcissus", "Narcissuses", and "Narcissi", but the British Compact Oxford English Dictionary lists just "Narcissi" and "Narcissuses".

The name Daffodil is derived from an earlier "Affodell", a variant of Asphodel. The reason for the introduction of the initial "d" is not known, although a probable source is an etymological merging from the Dutch article "de," as in "De affodil." From at least the sixteenth century "Daffadown Dilly" or "daffadown dilly" has appeared as a playful synonym of the name.

The name jonquil is sometimes used in North America, particularly in the southeastern, but strictly speaking that name belongs only to the rush-leaved Narcissus jonquilla and cultivars derived from it. In the southern United States, narcissus are sometimes referred to as buttercups.