The Mohorovicic discontinuity is also known as the Moho or the Mohor. It refers to the boundary between the Earth's crust and its underlying mantle. It is named after the seismologist Andrija Mohorovicic who discovered it in 1909. Other synonyms for it include the Moho boundary, the Moho surface, the crust-mantle boundary, and the Mohorovicic depth. It is a significant geological feature as it marks the change in composition and density between the crust and mantle layers. Its discovery and study have helped us gain a better understanding of the structure and dynamics of our planet's interior.