Crabs are capable of moving forward, but their leg joints make it far easier for them to move quickly by darting left or right. Because they’re the only animal famous for moving in this manner, “crabwise” is an evocative description of sideways motion. The word traces back to the Old English “crabba,” which hails from the Germanic “krabben,” meaning “to scratch, claw,” and the suffix “-wise,” which means “in the manner of.” “Crab walking” is also an exercise you can perform by raising yourself off the ground from a seated position so only your hands and feet touch the floor. From there, you can use your hands and feet to walk yourself from side to side in an especially crabwise motion.