The noun has 4 meanings:
Meaning #1:
sage of western North America to Central America having violet-blue flowers; widespread in cultivation
Synonyms: Salvia reflexa, Salvia lancifolia
Meaning #2:
Texas sage having intensely blue flowers
Synonyms: mealy sage, Salvia farinacea
Meaning #3:
blue-flowered sage of dry prairies of the eastern United States
Synonym: Salvia azurea
Meaning #4:
aromatic shrub of arid regions of western North America having hoary leaves
Synonyms: big sagebrush, Seriphidium tridentatum, Artemisia tridentata
