the.com/fins
Nature's joysticks: the wet world's answer to steering, braking, and showing off.
means The flat, often spined appendages fish and other aquatic animals use to swim, balance, and maneuver through water.
from From Old English finn, kin to Latin pinna, meaning feather or wing — water's version of flight gear.
Slang escapeIn poker, raising on nothing is finning.
Car fins1950s tailfins were jet-age aerodynamic theater, not function.
Walking finsSome fish use fins to stroll the seafloor.
Evolutionary heirloomYour limb bones descend from ancient fin rays.