ˌ ̷ ̷ ̷ ̷ˈmiz(h)ēəm noun
( plural perimy·sia -ēə)
Etymology: New Latin, irregular from peri- + Greek mys mouse, muscle + New Latin -ium — more at mouse
: the connective-tissue sheath that surrounds a muscle and sends partitions inward which form sheaths for the bundles of muscle fibers ; often : the portion sheathing the bundles — distinguished from epimysium