interdentally

Etymology tree
Proto-Indo-European *h₁én
Proto-Indo-European *h₁entér
Proto-Italic *n̥ter
Latin inter
Latin inter-bor.
English inter-
Middle French dentalbor.
Proto-Indo-European *h₃ed-
Proto-Indo-European *-ónts
Proto-Indo-European *h₃dónts
Proto-Italic *dents
Latin dēns
Proto-Indo-European *h₂el-der.?
Proto-Italic *-ālis
Latin -ālis
Late Latin dentālisbor.
English dental
English interdental
Proto-Indo-European *leyg-der.
Proto-Germanic *līkąder.
Proto-Germanic *-līkaz
Proto-Germanic *-ê
Proto-Germanic *-līkê
Proto-West Germanic *-līkē
Old English -līċe
Middle English -ly
English -ly
English interdentally
From interdental + -ly.