: congenital partial or total absence of the skull

Acrania

2 of 2

noun plural

in former classifications
: a division of the phylum Chordata comprising the hemichordates, tunicates, and lancelets and including all the chordates without true heads and anterior brains

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Cite this Entry

“Acrania.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/acrania. Accessed 7 Jul. 2026.

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