ARC - A directed edge.
ARM - The portion of the upper human appendage, from the shoulder to the wrist and sometimes including the hand.
ART - Human effort to imitate, supplement, alter, or counteract the work of nature.
CAR - A wheeled vehicle, drawn by a horse or other animal.
MAR - To spoil, to damage.
MAT - A flat piece of coarse material used for wiping one's feet, or as a decorative or protective floor covering.
RAM - A male sheep.
RAT - A medium-sized rodent belonging to the genus Rattus.
TAR - A black, oily, sticky, viscous substance, consisting mainly of hydrocarbons derived from organic materials such as wood, peat, or coal.
CAM - A turning or sliding piece which imparts motion to a rod, lever or block brought into sliding or rolling contact with it.
CART - A small, open, wheeled vehicle, drawn or pushed by a person or animal, more often used for transporting goods than passengers.
MART - A market.
CRAM - The act of cramming.
TRAM - A passenger vehicle for public use that runs on tracks in the road.
CARAT - A unit of weight for precious stones and pearls, equivalent to 200 milligrams.
TARMAC - The bituminous surface of a road.