Where does “обостря́ть” come from?
обостря́ть (Russian) comes from Russian обостри́ть, from Russian остри́ть, from Russian о́стрый, from Proto-Slavic ostrъ, from Proto-Balto-Slavic aśras, from Proto-Indo-European *h₂eḱrós, from Proto-Indo-European h₂eḱ- — sharp.
Ancestry of “обостря́ть”, step by step
Words derived from “обостря́ть”