| Word | Description |
| Harvested | the gathering of a ripened crop. |
| HDL cholesterol | “High-density lipoprotein” is one of the classes of lipoproteins that carry cholesterol in the blood. HDL is considered to be beneficial because it removes excess cholesterol from the blood and disposes of it. Hence HDL cholesterol is often termed "good" cholesterol. |
| Herbaceous | Not woody; having no persistent woody stems above ground |
| High blood cholesterol | Too much cholesterol in the blood, caused by eating foods high in saturated and trans fat, can increase your risk of heart disease. Cholesterol can build up on the walls of your arteries. This buildup of cholesterol is called plaque. Over time, plaque can cause narrowing of the arteries. This is called atherosclerosis (ath-er-o-skler-O-sis), or hardening of the arteries. |
| Honey | The thick, sweet liquid made by honey bees from the nectar of flowers. In general, the darker the color of the honey, the stronger the flavor. Honey is the oldest sweetener known. |
| Honeydew | A sticky, sugary secretion deposited on plants by insects such as aphids, scales, and whiteflies |
| Horticultural Oils | Commercially available horticultural oils are refined petroleum products. Homemade recipes that include vegetable oils also can be used. The type of vegetable oil however can greatly affect its effectiveness. Cottonseed oil is generally the most insecticidal of all the vegetable oils. Paraffinic oils are also used to control many insects and Spider Mites. |
| Hummus | A smooth thick mixture of mashed chickpeas, tahini, oil, lemon juice, and garlic, used especially as a dip for pita. |
| HVAC | Heating, Ventilation, and Air Conditioning equipment |
| Hyperglycemia (high blood sugar) | When the level of sugar in your blood is too high. |
| Hypoglycemia (low blood sugar) | When blood sugar (or blood glucose) concentrations fall below a level necessary to properly support the body's need for energy and stability throughout its cells. |
