Hardy coins the word “unvision” to mean literally “unsee.” In the poem’s context, it also has a figurative meaning: to destroy the vision of Emma he imagined or experienced in the garden.
To brood means to dwell on a subject while in an anxious or gloomy state of mind. With the word “broods,” Hardy personifies the stone, ascribing to it his own depressed emotional state.
"I went by the Druid stone..."See in text(Text of the Poem)
The poem begins with the description of an ancient stone in the garden at Max Gate. After moving into the house, Hardy discovered the large block of stone buried in the garden and arranged for it to be excavated, revealing charred human bones and ashes. Historical evidence to the contrary, Hardy chose to believe that the stone was the site of human sacrifices performed by Druids, priests of the Celtic tribes in Britain at the time of the Roman conquest.
