ART - Human effort to imitate, supplement, alter, or counteract the work of nature.
OAR - An implement used to propel a boat or a ship in the water, having a flat blade at one end, being rowed from the other end and being normally fastened to the vessel.
RAT - A medium-sized rodent belonging to the genus Rattus.
RAY - A beam of light or radiation.
ROT - To suffer decomposition due to biological action, especially by fungi or bacteria.
TAR - A black, oily, sticky, viscous substance, consisting mainly of hydrocarbons derived from organic materials such as wood, peat, or coal.
TOO - Likewise.
TOY - An inferior graffiti artist.
TRY - To attempt. Followed by infinitive.
OAT - Widely cultivated cereal grass, typically Avena sativa.
ROAR - To make a loud, deep cry, especially from pain, anger, or other strong emotion.
ROOT - The part of a plant, generally underground, that absorbs water and nutrients.
TRAY - Trouble; annoyance; anger.
ARTY - Pretending to artistic worth; high-flown.
ROTOR - A rotating part of a mechanical device, for example in an electric motor, generator, alternator or pump.
TARRY - To delay; to be late or tardy in beginning or doing anything.
ROTARY - Having or being capable of having rotation.
ORATOR - Someone who orates or delivers an oration.
ORATORY - The art of public speaking, especially in a formal, expressive, or forceful manner.