See e.g. Diodorus Siculus 3.62.5: "Dionysos was named twice-born by the ancients, counting it as a single and first birth when the plant is set in the ground and begins to grow, and as a second birth when it becomes laden with fruit and ripens its grape-clusters -- the god thus being considered as having been born once from the earth and again from the vine"), and generally LSJ s.v.