The meaning and significance of the Practicing Lineage is important to understand. Practicing Lineage is a term that was developed by Milarepa. Previously, the tradition was known as the "Lineage of the Sacred Word," which is actually a phrase that I am using again these days. In the Kagyu tradition, ka means "Logos," "sacred word," "command," "truth," and gyü means "thread" or "continuity"—which is close to the idea of lineage. In Milarepa's time, the Kagyu tradition became known as "Drubgyu": drub means "practice," and gyü means "lineage" or "line." The Practicing Lineage places a lot of importance on the necessity to practice, to sit or meditate. Without practicing, without understanding the meaning of practice, no real communication or development takes place in your understanding of Buddhism, or the buddhadharma.
From "The Practicing Lineage," in The Mishap Lineage: Transforming Confusion into Wisdom.