semispinalis
noun
semi·spi·na·lis
| \ -ˌspī-ˈnā-ləs
\
\
plural semispinales\ -ˌlēz
\
\
Medical Definition of semispinalis
: any of three muscles of the cervical and thoracic parts of the spinal column that arise from transverse processes of the vertebrae and pass to spinous processes higher up and that help to form a layer underneath the sacrospinalis muscle: