Devilline is a word that refers to something that is demonic or resembling the devil. Synonyms for this word include sinister, diabolic, malevolent, wicked, evil, and hellish. Other synonyms for devilline include demonic, satanic, fiendish, hellish, and infernal. These words all describe something that is evil, malicious, or dangerous, and may be associated with supernatural or demonic forces. Whether referring to a character in a book or a situation in real life, these synonyms provide a range of options for describing something that is truly menacing or diabolical.