Terrace: a ridge of earth run on a level around a slope or hillside to keep the land from washing.
Thorax: the middle part of the body of an insect. The thorax lies between the abdomen and the head.
Thermometer: an instrument for measuring heat.
Tillage: the act of preparing land for seed, and keeping the ground in a proper state for the growth of crops.
Transplant: a plant grown in a bed with a view to being removed to other soil; a technical term used by gardeners.
Tubercle: a small, wart-like growth on the roots of legumes.
Udder: the milk vessel of a cow.
Utensil: a vessel used for household purposes.
Variety: a particular kind. For example, the Winesap, Bonum, Æsop, etc., are different varieties of apples.
Ventilate: to open to the free passage of air.