What is the meaning of Flexor_digitorum_communis?

Flexor digitorum communis is a synonym of the flexor digitorum muscle

Four muscles of the hand and foot: flexor digitorum profundus muscle (flexor digitorum communis profundus), flexor digitorum superficialis muscle (flexor digitorum communis sublimis), flexor digitorum brevis muscle (flexor digitorum communis brevis), flexor digitorum longus muscle (flexor digitorum communis longus)

Source: wiktionary.org