| Word | Definitions | Synonyms |
|---|---|---|
| euthanasia | (noun) the act of killing someone painlessly (especially someone suffering from an incurable illness) | Synonyms: mercy killing |
| euthenics | (noun) the study of methods of improving human well-being and efficient functioning by improving environmental conditions | - |
| eutherian | (noun) mammals having a placenta; all mammals except monotremes and marsupials | Synonyms: eutherian mammal, placental, placental mammal |