The frog is an amphibian in the order Anura (meaning 'tail-less', from Greek an-, without + oura, tail), formerly referred to as Salientia (Latin saltare, to jump). The name frog derives from Old English frogga, (compare Old Norse frauki, German Frosch, older Dutch spelling kikvorsch), cognate with Sanskrit plava (frog), probably deriving from Proto-Indo-European praw = 'to jump'. A tree frog or tree toad is any frog that spends a major portion of its lifespan in an arboreal state. Two lineages