| Term | Definition |
| Eugenics | Science dealing with improving hereditary qualities |
| Eulogize | Write or speak in praise of someone |
| Euphemism | Substitution of a good expression for an unpleasant one |
| Euphoria | Sense of great happiness or well being |
| Euthanasia | Controversial practice of puttin to death a person suffering from an incurable, painfully distressing disease |
| Macro | Computer instruction standing for a series of steps |
| macrocosm | great world; universe |
| Macroscopic | Large enough to be visible to the naked eye |
| Amoral | not moral; without a sense of moral responsibility |
| amorphous | Without definite form; shapeless; unorganized |
| Anarchy | total absence of rule or government; confusion; disorder |
| Anemia | Lack of a normal number of red blood cells |
| Anesthesia | Loss of feeling or sensation resulting from ether, chloroform, novocaine |
| Anesthetic | drug that produces anesthesia |
| Anhydrous | destitute of water |
| anomaly | deviation from the common rule |
| Anonymous | nameless; of unknown or unnamed origin |
| apnea | temporary cessation of breathing |
| Asymptomatic | showing no symptoms of disease |
| Atheism | Godlessness; denial of the exsistance of a Supreme Being |
| Atrophy | Lack of growth, as from disuse, disease, or malnourishment |
| Atypical | unlike the typical |