brain·stem or brain stem 
(brānstĕm′)
(brānstĕm′)n.
The portion of the brain, consisting of the medulla oblongata, pons Varolii, and midbrain, that connects the spinal cord to the forebrain and cerebrum.
- prepositively
- prepossess
- prepossessing
- prepossessingly
- prepossession
- preposterous
- preposterously
- preposterousness
- prepotency
- prepotent
- prepotently
- preppie
- preppily
- preppiness
- preppy
- preprandial
- preprimary
- preprint
- preprocess
- preprocessor
- preproduction
- preprofessional
- preprogram
- prep school
- prepuberal