myalgia Syllabification: (my·al·gi·a)Pronunciation: /mīˈalj(ē)ə/Definition of myalgia noun pain in a muscle or group of muscles. Derivatives myalgicPronunciation: /-jik/ adjective Origin: mid 19th century: modern Latin, from Greek mus 'muscle' + -algiamyalgia in other Oxford dictionaries Definition of myalgia in the British & World English dictionary