brainstem

n. (Anatomy) part of the lower brain that resembles a stem and connects the brain to the spinal cord

The brain stem is the lower part of the brain, adjoining and structurally continuous with the spinal cord. Most sources consider the pons, medulla oblongata, and midbrain all to be part of the brainstem.Differentiation of the brain stem from the cerebrum is complex, with regard to both anatomy and taxonomy. Some taxonomies describe the brain stem as the medulla and mesencephalon, whereas others include diencephalic regions.
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Brainstem the stemlike portion of the brain connecting the cerebral hemispheres with the spinal cord, and comprising the pons, medulla oblongata, [more]Brainstem - Community and Resources

Noun
1. the part of the brain continuous with the spinal cord and comprising the medulla oblongata and pons and midbrain and parts of the hypothalamus
(synonym) brain-stem, brain stem
(hypernym) neural structure
(part-holonym) brain, encephalon
(part-meronym) medulla oblongata, medulla, bulb