It means heals. It is the name of many plants mostly with medicinal uses. It is also the name of a genus of plants that belongs to the family Lamiaceae. There are about 900 different species which make it the most numerous genus.
sage-refers to the expression : medicinal plant, erect, robust, very smelly, with obtuse leaves, scalloped and basal rosette shape; it is used in medicine as a healer