Cusp

Definition

A cusp is the dividing line that opens a house in the chart. Every house begins at a cusp expressed as a degree and sign of the zodiac, and the cusp sets the tone for the affairs of the house that follows it. The four most loaded cusps are the angular ones (the Ascendant, Midheaven, Descendant, and Imum Coeli) because they sit on the chart's main axes.

In context

If your seventh-house cusp falls at twenty degrees of Libra, the ruler of Libra (Venus) becomes the planetary voice of your seventh house even when no planet occupies the house. The cusp is the doorway: whatever sign sits on it colors how you enter that area of life and who you tend to meet there. House content matters, but the cusp sets the threshold the content has to cross to register on the page.

To go deeper

Cusp is central to the angular framework of a chart:

• Ascendant: first-house cusp, the eastern horizon.
• Midheaven: tenth-house cusp, the upper meridian.
• House system: rule that decides cusp positions.