英语词源字典 - 在线词源网站

class [class 词源字典]: class: [16] Latin classis originally denoted ‘the people of Rome under arms, the ancient Roman army’; it appears to come from an earlier unrecorded *qladtis, a derivative of the base *qel- ‘call’, which points to an underlying sense ‘call to arms’. Under the terms of the constitution attributed to Servius Tullius, a 6thcentury BC king of Rome, the army, and hence the people, was divided into six such classes, membership of each based originally on the amount of land held, and latterly on wealth in money terms.

English first adopted the word in this antiquarian sense (which provided the basis for the modern application to social class), but its widespread use in the language probably began in the sense ‘group of pupils’. The derivatives classic [17] and classical [16] come from Latin classicus, probably via French classique; in Latin, the adjective signified ‘of the highest class of Roman citizen’, whence the word’s presentday approbatory connotations.
[class etymology, class origin, 英语词源]
democracy: democracy: [16] Democracy means literally ‘government by the populace at large’. It comes via Old French democratie and medieval Latin dēmocratia from Greek dēmokratíā, a compound formed from demos ‘people’ and -kratíā ‘rule’, a derivative of the noun krátos ‘power, authority’, which has contributed a number of terms for types of government to English.

The original meaning of Greek demos was ‘district, land’, but eventually it came to denote the people living in such a district, particularly the ordinary people considered as a social class participating in government – hence democracy. The derivative democrat [18] was coined in French at the time of the Revolution.
=> epidemic
dinner: dinner: [13] The etymological meaning of dinner is ‘breakfast’. The word comes ultimately from an unrecorded Vulgar Latin verb *disjūnāre, a compound formed from the prefix dis- ‘un-’ and jējūnus ‘fasting, hungry’ (source of English jejune [17]): hence, ‘break one’s fast’. Old French adopted it in two phases: as desiuner, which became modern French déjeuner (originally ‘breakfast’ but later ‘lunch’), borrowed by English in the 18th century; and as disner.

In later Old French this developed into diner (source of English dine [13]), which came to be used as a noun – from which English acquired dinner. In English it has always denoted the main meal of the day, although the timing of this has varied over the centuries, and continues to do so, according to region, social class, etc.
=> jejune
underclass (n.): "subordinate social class," 1894, from under (adj.) + class (n.). A loan-translation of Swedish underklass.
non-U: "(Of language or social behaviour) not characteristic of the upper social classes; not socially acceptable to certain people", 1950s: from non- + U³.