Definition of acranial in English:

acranial

adjective

Zoology Medicine
  • Affected with acrania; lacking (part of) the skull.

Origin

Mid 19th century. From scientific Latin acranius + -al. With the medical use compare acrania. With the use in zoology, compare scientific Latin Acrania, neuter plural, applied by Haeckel to primitive vertebrates lacking a bony brain case, and compare also acraniate.

Pronunciation:

acranial

/(ˌ)eɪˈkreɪnɪəl/