diseased characterized by inflammation of the mucous membrane of the large intestine, late 14c., dissenterie, from Old French disentere (13c.) and directly from Medieval Latin dysenteria, from Greek dysenteria, coined by Hippocrates, from dys- "bad, abnormal, difficult" (see dys-) + entera "intestines, bowels," from PIE *enter "between, among," comparative of root *en "in." Related: Dysenteric.

"failure to function, abnormality or impairment of function," 1914, from dys- "bad, abnormal, difficult" + function (n.). Originally in anatomy and medicine; in sociology by 1949.

 "study of the factors producing genetic deterioration, also loosely, "the carrying on of the species by the worst members," 1906, from dys- + ending from eugenics. Hence dysgenic "having or causing a detrimental effect on the race" (1909).

"a difficulty in reading due to a condition of the brain," 1885, from German dyslexie (1883), from Greek dys- "bad, abnormal, difficult" (see dys-) + lexis "word" (taken as "reading"), from legein "speak" (from PIE root *leg- (1) "to collect, gather," with derivatives meaning "to speak (to 'pick out words')") + abstract noun ending -ia. Dyslexic (n.) is recorded by 1946; dyslectic (adj.) by 1962.

Professor Berlin has written a very interesting monograph upon the disease called dyslexia, which he believes allied to the alexia, or word-blindness of Kussmaul. He gives a clinical history of six cases, collected during a period of twenty-three years, all having this peculiarity, that they could read aloud the average type, Jaeger three to five, only a few words in succession. These words were correctly spoken and without confusion or stammering, but as soon as a few words had been read the patients seemed anxious to get rid of the book, and, on being questioned, stated that they had an unpleasant feeling which they could not well define. [The Satellite of the Annual of the Universal Medical Sciences, Philadelphia, November 1887]

"dispraise," the opposite of eulogy, 1837; see dys- + -logy. Related: Dyslogistic (1802). 

1690s, "causing dyspepsia" (a sense now obsolete); by 1789 as "pertaining to dyspepsia;" by 1822 as "suffering from dyspepsia;" from Greek dyspeptos "hard to digest," from dys- "bad, difficult" (see dys-) + peptos "digested," from peptein "to digest" (from PIE root *pekw- "to cook, ripen"). Also "characteristic of one suffering from dyspepsia" (depressed, pessimistic, misanthropic), by 1894; dyspepsical in this sense is by 1825.

"substitution of a vulgar or derogatory word or expression for a dignified or normal one," 1873, from Greek dys- "bad, abnormal, difficult" (see dys-) + phēmē "speech, voice, utterance, a speaking," from phanai "speak" (from PIE root *bha- (2) "to speak, tell, say"); Greek dysphemia meant "ill language, words of ill omen"). The opposite of euphemism. Rediscovered 1933 from French formation dysphémisme (1927, Carnoy).

The French psychologist Albert J. Carnoy gave an extensive definition in his study Le Science du Mot, which in translation runs: "Dysphemism is unpitying, brutal, mocking. It is also a reaction against pedantry, rigidity and pretentiousness, but also against nobility and dignity in language" (1927, xxii, 351). [Geoffrey L. Hughes, "An Encyclopedia of Swearing," 2006]

"impatience under affliction," 1842, from Greek dysphoria "pain hard to be borne, anguish," etymologically "hard to bear," from dys- "bad, hard" (see dys-) + pherein "to carry" (from PIE root *bher- (1) "to carry").

"abnormal growth or development of tissue, cells, etc.," 1935, Modern Latin, from dys- "abnormal, imperfect" + -plasia "formation, growth, development." Related: Dysplastic.

element, obtained 1906 from an earth discovered in 1886, the last to be extracted from the complex earth called yttria, and named dysprosia in reference to the difficulty of obtaining it, from Greek dysprositos "hard to get at, difficult of access," from dys- "bad, difficult" (see dys-) + prositos "approachable." With metallic element suffix -ium.