10 letters · 15 points in Scrabble
adjective showing the cunning or ingenuity or wickedness typical of a devil
adjective extremely evil or cruel; expressive of cruelty or befitting hell
originEtymology tree English diabolic 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 diabolical From diabolic + -al.
Etymology from Wiktionary, CC BY-SA 3.0