(Druids Trees, Tree lore, Celtic) - Druids loved trees and often visited trees and woods to meditate there, held ceremonies, or simply communed with Nature. The most likely derivation for 'Druid' is from the word for oak. Therefore the word Druid means 'One with knowledge of the oak' or 'Wise person of the oak'. Those who possessed knowledge of the oak possessed knowledge of all the trees. The Druid was one with 'knowledge of the trees' and was a 'Forest Sage'.