Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
demoniac is a noun and adjective meaning "someone who acts as if possessed by a demon". It carries 2 recorded senses.
someone who acts as if possessed by a demon
of, pertaining to, or like a demon or possession by a demon
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for demoniac come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.