spersed > scattered (aphetic form of "dispersed")
2 And through the world of waters wide and deep, 3 To Morpheus' house does hastily repair.
repair > go, betake himself
4 Amid the bowels of the earth full steep,
full > very, exceedingly
5 And low, where dawning day does never peep, 6 His dwelling is; there Tethys his wet bed
Tethys > (A marine goddess, wife of Oceanus; the sea)
7 Does ever wash, and Cynthia still does steep
Cynthia > (Diana in her aspect as goddess of the moon; the moon itself. See 203.31:2) still > continuously
8 In silver dew his ever-drooping head, 9 While sad Night over him her mantle black does spread.