| Term | Definition |
| dys | bad ill difficult |
| dysentery | inflammation of the large intestine usually caused by harmful micro organism in food or water |
| dyslexia | impairment of the ability to read |
| dyslogistic | expressing disapproval or harsh criticism uncomplimentary |
| dyspepsia | poor digestion indigestion |
| dysphagia | difficulty in swalowing |
| dysphasia | speech difficulty resulting from brain injury |
| dysphoria | sense of great unhappiness or dissatisfaction |
| dystopia | imaginary place where living conditions are dreadful |
| dystrophy | faulty nutriton |
| eu | good well advantageous |
| eugenics | science dealing with improving the hereditary qualities genes of the human race |
| eulogize | write or speak in praise of someone |
| eupepsia | good digestion |
| euphemism | substitution of a good expression fro an unpleasant one example passed away for death |
| euphonious | pleasing in sound |
| euphoria | sense of great happiness or well being |
| euthanasia | the act or practice of ending the life of an indivdual suffereing from a terminal illness or an incurable condition as by lethal injection or the suspension of extraordinary medical treatment |
| euthenics | science dealing with the improving living conditions |
| macro | large long |
| micro | small minute |
| macrocosm | great world universe |
| macron | horizontal mark indicationg the vowel over which it is placed is long |
| macroscopic | large enough to be seen with the naked eye |
| microbe | microorganism microscopic living animal or plant |
| microbicide | agent or substance that destroys microbes |
| microdont | having small teeth |
| microsecond | millionth of a second |
| microwatt | millionth of a watt |
| dysfunction | abnormal functioning as of an organ of the body |