Natal significance: The South Node is the point in the southern hemisphere of the chart where the paths of the Sun and Moon cross in the sky. Like the North Node, which is always exactly opposite it, the South Node is a karmically significant point relating to your growth as an individual. But unlike the receptive North Node, the South Node signifies blockage from spiritual evolution. The South Node shows the kind of psychological and karmic baggage we bring to our experience, the nonconstructive habits, beliefs and patterns which are so deeply ingrained in us that we fall back on them rather than being open to new directions of growth.
Transiting significance: When a transiting planet activates your South Node, you may be tempted to regress, to rely on familiar but unproductive modus operandi which do nothing to further your development as an individual and might even set you back. (Around the time of his suicide, Kurt Cobain's South Node, natally close to his Neptune -- planet of drugs and self-deception -- was strongly activated by transit.) But don't despair -- since the Nodes are opposite, every transit that activates the South Node also activates the North -- even if it may be a greater challenge to rise to the occasion of making use of positive North Node energy.