Short answers, pulled from the story.
Adonis was the mortal lover of both Aphrodite and Persephone in Greek mythology and was considered the ideal of male beauty in classical antiquity. He was gored by a wild boar during a hunt and died in Aphrodite's arms. His death was commemorated annually through the festival of Adonia.
The name Adonis derives from the Canaanite word adōn, meaning "lord." The same root produced the Hebrew title Adonai, used for God in the Hebrew Bible. Most modern scholars trace the myth of Aphrodite and Adonis to a Levantine version of the earlier Mesopotamian story of Inanna and Dumuzid, also known as Ishtar and Tammuz.
Adonis was mortally wounded by a wild boar while hunting and died in Aphrodite's arms. Three competing versions name different divine agents who sent the boar: Ares out of jealousy, Artemis seeking revenge for the death of Hippolytus, and Apollo punishing Aphrodite for blinding his son Erymanthus. Where Adonis's blood fell, anemone flowers grew.
The Adonia was an annual midsummer festival celebrated by Greek women, reaching its greatest popularity in Athens during the mid-fifth century BC. Women planted fast-growing crops such as lettuce, fennel, wheat, and barley in small baskets or pottery, set them on rooftops to wither in the summer heat, then mourned loudly and carried an effigy of Adonis to the sea. The ritual concluded when the effigy and the withered plants were thrown into the water.
Shakespeare's Venus and Adonis, published in 1593, was the most popular of all his works printed during his lifetime, with six editions appearing before his death. The poet Richard Barnfield praised it in 1605, writing that it placed Shakespeare's name "in fames immortall Booke." Its influence extended to the Italian poet Giambattista Marino, whose 1623 epic L'Adone outsold Shakespeare's First Folio.
The Scottish anthropologist James George Frazer argued in The Golden Bough, first published in 1890, that Adonis was a prime example of the dying-and-rising god archetype found in all world cultures. Scholars Eddy and Boyd (2007) challenged this, arguing that Adonis's time in the underworld is not a true death and resurrection. Origen, the early Christian scholar, recorded that the rites for Adonis involved mourners first weeping because "he has died" and then rejoicing because "he has risen from the dead," using the Greek phrase apo nekron anastanti.