TORTOISE. (KJV tr. of צָב, H7370, Lev 11:29). RSV Great Lizard. This is found once only in a list of unclean animals, and the KJV tr. is almost certainly wrong (see Lizard). However, tortoises of several species, mostly Testudo graeca and leithii, are common today in Pal. They live in a range of habitats other than true desert, and are most active in spring and early summer, taking cover in the hottest weather and hibernating for part of the winter. These land tortoises are vegetarians, in contrast to the Terrapins, or Pond Tortoises, which feed on aquatic animal life and are common in some rivers and fish-ponds.
International Standard Bible Encyclopedia (1915)
tor’-tus, tor’-tis, tor’-tois. (the King James Version) (tsabh, the Revised Version (British and American) "great lizard"; compare the Arabic word, dabb, the thorny-tailed lizard): The word tsabh occurs as the name of an animal only in Le 11:29, being the third in the list of unclean "creeping things."
The same word is found in Isa 66:20, translated "litters," and in Nu 7:3, where `eghloth tsabh is translated "covered wagons." Gesenius derives the word, in all senses, from the root cabhabh, "to move gently," "to flow"; compare Arabic dabba, "to flow." The Arabic noun dabb is Uromastix spinipes, the Arabian thorny-tailed lizard. This lizard is about 18 inches long, its relatively smooth body being terminated with a great tail armed with rings of spiny scales. The Arabs have a familiar proverb, ’a`kad min dhanab ud-dabb, "knottier than the tail of the dabb." The Septuagint has for tsabh in Le 11:29 ho krokodeilos ho chersaios, the English equivalent of which, "land-crocodile," is used by the Revised Version (British and American) for the fifth in the list of unclean "creeping things," koach, the King James Version "chameleon."
The writer does not know what can have led the translators of the King James Version to use here the word "tortoise." Assuming that the thorny-tailed lizard is meant, the "great lizard" of the Revised Version (British and American) may be considered to be a fair translation.