ART - Human effort to imitate, supplement, alter, or counteract the work of nature.
MAT - A flat piece of coarse material used for wiping one's feet, or as a decorative or protective floor covering.
MAY - The hawthorn bush or its blossoms.
RAT - A medium-sized rodent belonging to the genus Rattus.
RAY - A beam of light or radiation.
TAR - A black, oily, sticky, viscous substance, consisting mainly of hydrocarbons derived from organic materials such as wood, peat, or coal.
YAM - Any climbing vine of the genus Dioscorea in the Eastern and Western hemispheres, usually cultivated.
ARMY - A large, highly organized military force, concerned mainly with ground (rather than air or naval) operations.
TRAY - Trouble; annoyance; anger.
MART - A market.
TRAM - A passenger vehicle for public use that runs on tracks in the road.
ARTY - Pretending to artistic worth; high-flown.
MARRY - Indeed!, in truth!; a term of asseveration.
TARRY - To delay; to be late or tardy in beginning or doing anything.
MARTYR - One who willingly accepts being put to death for adhering openly to one's religious beliefs; notably, saints canonized after martyrdom.