A saddle connection on a translation surface $\omega$ is a geodesic in the flat metric determined by $\omega$ joining two zeros with no zeros in its interior.
Athreya, Jayadev S., and Howard Masur. Translation Surfaces. Vol. 242. American Mathematical Society, 2024. Quote from p.26.
Q. Why is it called a "saddle connection"? In particular, why saddle?