diagnostically

Etymology tree
Proto-Indo-European *dwóh₁
Proto-Indo-European *dwísder.
Ancient Greek διά (diá)
Ancient Greek δια- (dia-)
Proto-Indo-European *ǵneh₃-
Proto-Indo-European *-sḱéti
Proto-Indo-European *ǵn̥h₃sḱétider.
Proto-Hellenic *gignṓskō
Ancient Greek γῐγνώσκω (gĭgnṓskō)
Ancient Greek δῐαγῐγνώσκω (dĭagĭgnṓskō)
Proto-Indo-European *-tis
Ancient Greek -τις (-tis)
Ancient Greek -σῐς (-sĭs)
Ancient Greek δῐᾰ́γνωσῐς (dĭắgnōsĭs)
▲
Ancient Greek -σῐς (-sĭs)
Proto-Indo-European *-kos
Ancient Greek -κός (-kós)
?
Proto-Indo-European *-tós
Proto-Hellenic *-tós
Ancient Greek -τος (-tos)
▲
Ancient Greek -κός (-kós)
?
Ancient Greek -τῐκός (-tĭkós)
▲
Ancient Greek δῐᾰ- (dĭă-)
Proto-Indo-European *ǵneh₃-
Proto-Indo-European *-tis
Proto-Indo-European *ǵneh₃tisder.
Ancient Greek γνῶσις (gnôsis)
▲
Ancient Greek -τῐκός (-tĭkós)
Ancient Greek γνωστῐκός (gnōstĭkós)
Ancient Greek δῐαγνωστῐκός (dĭagnōstĭkós)bor.
English diagnostic
Proto-Indo-European *h₂el-der.?
Proto-Italic *-ālis
Latin -ālisbor.
Old French -albor.
▲
Latin -ālis
Old French -elbor.
▲
Latin -ālisbor.
Middle English -al
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
Middle English -ally
English -ally
English diagnostically
From diagnostic + -ally.