organ (n.)
fusion of late Old English organe, and Old French orgene (12c.), both meaning "musical instrument," both from Latin organa, plural of organum "a musical instrument," from Greek organon "implement, tool for making or doing; musical instrument; organ of sense, organ of the body," literally "that with which one works," from PIE *werg-ano-, from root *werg- "to do" (cognates: Greek ergon "work," orgia "religious performances;" Armenian gorc "work;" Avestan vareza "work, activity;" Gothic waurkjan, Old English wyrcan "to work," Old English weorc "deed, action, something done;" Old Norse yrka "work, take effect").

Applied vaguely in late Old English to musical instruments; sense narrowed by late 14c. to the musical instrument now known by that name (involving pipes supplied with wind by a bellows and worked by means of keys), though Augustine (c.400) knew this as a specific sense of Latin organa. The meaning "body part adapted to a certain function" is attested from late 14c., from a Medieval Latin sense of Latin organum. Organist is first recorded 1590s; organ-grinder is attested from 1806.