bidialectal

Etymology tree
Proto-Indo-European *dwóh₁
Proto-Indo-European *dwi-
Proto-Italic *dwi-
Latin bi-bor.
English bi-
Proto-Indo-European *dwóh₁
Proto-Indo-European *dwísder.
Ancient Greek διά (diá)
Ancient Greek δῐᾰ- (dĭă-)
Proto-Indo-European *leǵ-der.
Proto-Indo-European *léǵ-e-ti
Proto-Hellenic *légō
Ancient Greek λέγω (légō)
Ancient Greek διαλέγομαι (dialégomai)
Proto-Indo-European *-tós
Proto-Hellenic *-tós
Ancient Greek -τος (-tos)
Ancient Greek δῐᾰ́λεκτος (dĭắlektos)bor.
Latin dialectoslbor.
Middle French dialectebor.
English dialect
Proto-Indo-European *h₂el-der.?
Proto-Italic *-ālis
Latin -ālisbor.
Old French -albor.
▲
Latin -ālis
Old French -elbor.
▲
Latin -ālisbor.
Middle English -al
English -al
English dialectal
English bidialectal
From bi- + dialectal.