saber-toothed tiger, sabertooth(noun)

any of many extinct cats of the Old and New Worlds having long swordlike upper canine teeth; from the Oligocene through the Pleistocene

saber-toothed tiger(Noun)

Any of numerous species of prehistoric cat-like mammals (genus Smilodon), characterized by massive, but short, legs and two large canine teeth, each about seven inches long and shaped like sabers.