Possible Clues:

• Indigo product
• West Indian shrub, source of indigo
• Source of dye popular over in Alabama
• Shrub providing indigo
• A nothing at all that may die, so it sounds
• That sounds as if a nothing can die
• The sort of a nothing that make one die, by the sound of it
• Blue as a result of getting a duck?
• The sort of nothing to make this die, by the sound of it
• Sound die for a nothing at all