| Term | Definition |
| hyperbole | extravagant exaggeration of statement |
| hyperemia | superbundance of blood |
| hyperopia | farisightendness |
| hypersensitive | excessively sensitive, supersensitive |
| hypertrophy | enlargement of a part or organ, as from excessive use |
| hypodermic | injected under the skin |
| hypothesis | theory or supposition assumed as a basis fro reasoning (literally, something placed under) |
| hypothetical | assumed without proof for the purpose of reasoning, conjectural |
| endocrine | secreting internally |
| endogamy | marriage within the tribe, caste, or a social group |
| exogamy | marriage outside the tribe, caste, or social group |
| endogenous | produced from within; due to internal causes |
| exogenous | produced from without; due to external causes |
| endosmosis | osmosis inward |
| endocarditis | inflammation of the lining of the heart |
| endoderm | membrane-like tissue lining the digestive tract |
| endoparasite | pararsite living within another plant |
| exoteric | external, exterior, readily understandable |
| exotic | 1. introduced from a foreign country 2. exitingly strange |
| endophyte | plant growing within another plant |