adjective/oneˈɾoso/
onerous
Etymology tree Proto-Indo-European *h₃enh₂- Proto-Indo-European *-os Proto-Indo-European *h₃énh₂os Proto-Italic *onos Latin onus Proto-Indo-European *h₃ed- Proto-Indo-European *-os Proto-Indo-European *h₃édosder.? Proto-Italic *-ŏ̄dsos? Old Latin -ōssus Latin -ōsus Latin onerōsusbor. Spanish oneroso Borrowed from Latin onerōsus.