Definition of saber-toothed cat
1
: any of various extinct carnivorous cats (such as genus Smilodon) that were widely distributed in the Oligocene through the Pleistocene of both the Old and New World, are characterized by elongation of the upper canines into curved, piercing or slashing, dagger-like weapons and in enlargement of the gape with corresponding muscular and skeletal changes, and that constitute a distinct felid subfamily (Machairodontinae)
2
: any of various extinct North American, Eurasian, and African catlike carnivores (as of the genera Hoplophoneus and Nimravus of the family Nimravidae) of the Late Eocene to Late Miocene that resemble the typical saber-toothed cats
