Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
nanocephalic is an adjective meaning "having an abnormally small head and underdeveloped brain". It carries one recorded sense.
having an abnormally small head and underdeveloped brain
“a nanocephalic dwarf”
Definitions, synonyms and semantic relations for nanocephalic come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.