Etymology
Borrowed from Middle French Madagascar, from Madageiscar, popularly reputed as a corrupted transliteration of Mogadishu by Marco Polo's misreading of Arabic. The maps of particular interest are that of al-Idrisi in the 12th century, who produced the Tabula Rogeriana, the most advanced world map at the time.
The actual misconstrued term was Arabic جَزِيرَة المَالَائِيّ (jazīrat al-mālāʔiyy, “The Island of Mālāī”) listed alongside Arabic جَزِيرَة القَمَر (jazīrat al-qamar, “The Island of the Moon”) which lent its name to Comoros; Madagascar however likely being the original based on its dimensions.
The map in question warps the direction of Africa's east coast to be parallel to the coast of southeast Asia, prompting a conflation of the regions furthest east and furthest south, in the reaches