What is the origin of the word "orca", which is used when talking about a killer whale?

For the Latin word orca, meaning whale or a corruption of the Greek word oryx.

https://en.wikipedia.org/wiki/Killer_whale#Common_names

orca (n.) Look up orca at Dictionary.com

"killer whale," introduced as a generic term for the species by 1841, from earlier use in scientific names, from Latin orca "cetacean, a kind of whale." Earlier in English, orc, ork "large whale" (c.1590), from French orque, had been used vaguely of sea monsters (see orc).

http://www.etymonline.com/index.php?term=orca


"Word Origin and History for orca

"killer whale," 1846, introduced as a generic term for the species by J. Richardson & J.E. Gray in "The zoology of the voyage of HHS 'Erebus' & 'Terror,' " from L. orca "cetacean, a kind of whale." Earlier in Eng., orc, ork "large whale" (c.1590), from Fr. orque, had been used vaguely of sea monsters (see orc ).
Online Etymology Dictionary, © 2010 Douglas Harper

http://dictionary.reference.com/browse/orca

Orcas were given the name 'killer whale' by ancient sailors' observations of groups of orcas hunting and preying on larger whale species. They called orcas asesina ballenas, or 'whale killer' - a term that was eventually flipped around to the easier 'killer whale'. Their Latin name, Orcinus orca, also reflects this observation of orcas feeding on large whales. Orcinus translates to 'of the kingdom of the dead,' and orca refers to a kind of whale.

https://us.whales.org/whales-dolphins/facts-about-orcas/