DOG - A mammal, Canis lupus familiaris, of the genus Canis that has been domesticated for thousands of years, of highly variable appearance due to human breeding.
DUG - Mammary gland on domestic mammal containing more than two breasts.
DUO - A twosome, especially musicians.
GOD - A deity:.
GUN - A very portable, short firearm, for hand use, which fires bullets or projectiles, such as a handgun, revolver, pistol, or Derringer.
NOD - To incline the head up and down, as to indicate agreement.
OUR - Belonging to us.
RUG - A partial covering for a floor.
RUN - Act or instance of running, of moving rapidly using the feet.
URN - A vase with a footed base.
DON - A university professor, particularly one at Oxford or Cambridge.
GNU - A large antelope native to Africa having curved horns.
DRUG - A substance used to treat an illness, relieve a symptom, or modify a chemical process in the body for a specific purpose.
DUNG - Manure; animal excrement.
RUNG - A crosspiece forming a step of a ladder; a round.
UNDO - To reverse the effects of an action.
DOUR - Stern, harsh and forbidding.
ROUND - Circular or cylindrical; having a circular cross-section in one direction.
GOURD - Any of the climbing or trailing plants from the family Cucurbitaceae, which includes watermelon, pumpkins and cucumbers.
GROUND - The surface of the Earth, as opposed to the sky or water or underground.