What is the origin of the word tiger?

The Word "tiger" is taken from the Greek Word "tigris", which is possibly derived from a Persian source meaning "arrow", a reference to the animal's speed and also the origin for the name of the Tigris river. In American English, "tigress" was first recorded in 1611. It was one of the many species originally described by Linnaeus in his 18th century work, Systema Naturae: he called it Felis tigris. The generic component of its scientific designation, Panthera tigris, is often presumed to derive from Greek pan- ("all") and theron("beast"), but this may be a folk etymology. Although it came into English through the classical languages, panthera is probably of East Asian origin, meaning "the yellowish animal", or "whitish-yellow".

-- From Wikipedia