peroneus tertius
noun
peroneus ter·ti·us
-ˈtər-shē-əs 
: a branch of the extensor digitorum longus muscle that arises especially from the lower portion of the fibula, inserts on the dorsal surface of the base of the fifth metatarsal bone, and flexes the foot dorsally and assists in everting it
Cite this Entry
“Peroneus tertius.” Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/peroneus%20tertius. Accessed 26 Nov. 2025.
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