mako (n.) Look up mako at Dictionary.com
"large blue shark," listed as 1727 in OED, from "The History of Japan," English translation of Engelbert Kaempfer's German manuscript; however this is claimed by some to be an error, and some say Kaempfer's word represents Japanese makkô(-kujira) "sperm whale." But the description in the text fits neither the shark nor the whale. The word is ultimately from Maori mako "shark, shark's tooth," which is of uncertain etymology. If the 1727 citation is an error, the earliest attested use is 1820, from a book on New Zealand languages.