Etymology tree Proto-Indo-European *h₂ews- Proto-Indo-European *-s Proto-Indo-European *h₂éwss? Proto-Indo-European *-teros Proto-Indo-European *h₂éwsteros Proto-Italic *austeros Latin auster Proto-Indo-European *h₂el-der.? Proto-Italic *-ālis Latin -alis Latin australisbor. English austral Borrowed from Latin australis (“southern”).