a. (Biol.) 1. Relating to autogenesis; self-generated. [ 1913 Webster ]

2. (Phys. Geog.) Pertaining to, controlled by, or designating, a system of self-determined drainage. [ Webster 1913 Suppl. ]

. (Phys. Geog.) A system of natural drainage developed by the constituent streams through headwater erosion. [ Webster 1913 Suppl. ]

. (Phys. Geog.) A system of land forms produced by the free action of rain and streams on rocks of uniform texture. [ Webster 1913 Suppl. ]