Old English ceorl "peasant, one of the lowest class of freemen, man without rank," from Proto-Germanic *kerlaz, *karlaz (source also of Old Frisian zerl "man, fellow," Middle Low German kerle, Dutch kerel "freeman of low degree," German Kerl "man, husband," Old Norse karl "old man, man").
It had various meaning in early Middle English, including "man of the common people," "a country man," "husbandman," "free peasant;" by 1300, it meant "bondman, villain," also "fellow of low birth or rude manners."
For words for "common man" that acquire an insulting flavor over time, compare boor, villain. In this case, however, the same word also has come to mean "king" in many languages (such as Lithuanian karalius, Czech kral, Polish król) via Charlemagne.
c. 1300, "bondsman; common man, man of low birth," from Old Norse karl "man" (as opposed to "woman"), "male, freeman," from Proto-Germanic *karlon- (source also of Dutch karel "a fellow," Old High German karl "a man, husband"). The same Proto-Germanic source produced Old English ceorl "man of low degree" (see churl) and the masc. proper name Carl and, via French and Latin, Charles.
The Mellere was a stout carle for the nones [Chaucer]
c. 1300 (late 12c. as a surname), "base or low-born rustic," from Anglo-French and Old French vilain "peasant, farmer, commoner, churl, yokel" (12c.), from Medieval Latin villanus "farmhand," from Latin villa "country house, farm" (from PIE root *weik- (1) "clan"). Meaning "character in a novel, play, etc. whose evil motives or actions help drive the plot" is from 1822.
The most important phases of the sense development of this word may be summed up as follows: 'inhabitant of a farm; peasant; churl, boor; clown; miser; knave, scoundrel.' Today both Fr. vilain and Eng. villain are used only in a pejorative sense. [Klein]
Old English eorl "brave man, warrior, leader, chief" (contrasted with ceorl "churl"), from Proto-Germanic *erlaz, which is of uncertain origin. In Anglo-Saxon poetry, "a warrior, a brave man;" in later Old English, "nobleman," especially a Danish under-king (equivalent of cognate Old Norse jarl), then one of the viceroys under the Danish dynasty in England. After 1066 adopted as the equivalent of Latin comes (see count (n.1)).
Earl Gray tea (1880s) was originally a Chinese tea blended with bergamot oil, supposedly from a recipe given to Charles, second Earl Gray (the Whig prime minister), in the 1830s, but perhaps it was named later, commercially, in his honor.
late 15c., "servant, serving-man, slave," from Old French serf "vassal, servant, slave" (12c.), from Latin servum (nominative servus) "slave" (see serve (v.)). The word had fallen from use in this sense by 18c. The meaning "lowest class of cultivators of the soil in Poland, Russia, and other continental European countries, living in conditions of modified slavery" is by 1610s.
It was use from 1761 by modern writers in reference to medieval Europeans attached to the land and incapable of owning property. Contemporary Anglo-Latin records used nativus, villanus, or servus. Middle English sometimes included this class under bond-man, or theu (from Old English þeow), also carl or churl.
mid-13c., boie "servant, commoner, knave" (generally young and male); c. 1300, "rascal, ruffian, knave; urchin," mid-14c. as "male child before puberty" (possibly an extended sense from the "urchin" one). A word of unknown origin.
Possibly from Old French embuie "one fettered," from Vulgar Latin *imboiare, from Latin boia "leg iron, yoke, leather collar," from Greek boeiai dorai "ox hides." (Words for "boy" double as "servant, attendant" across the Indo-European map -- compare Italian ragazzo, French garçon, Greek pais, Middle English knave, Old Church Slavonic otroku -- and often it is difficult to say which meaning came first.)
But it also appears to be identical with East Frisian boi "young gentleman," and perhaps with Dutch boef "knave," from Middle Dutch boeve, perhaps from Middle Low German buobe. This suggests a gradational relationship to babe. For a different conjecture: Used slightingly of young men in Middle English, also in familiar or contemptuous use of criminal toughs or men in the armed services. In some local uses "a man," without reference to age (OED lists "in Cornwall, in Ireland, in the far West of the U.S."). Meaning "male negro slave or Asian personal servant of any age" attested from c. 1600. Extended form boyo is attested from 1870. Emphatic exclamation oh, boy is attested by 1917. Boy-meets-girl "typical of a conventional romance" is from 1945; the phrase itself is from 1934 as a dramatic formula. Boy-crazy "eager to associate with males" is from 1923.
In Old English, only the proper name Boia has been recorded. ME boi meant 'churl, servant' and (rarely) 'devil.' In texts, the meaning 'male child' does not antedate 1400. ModE boy looks like a semantic blend of an onomatopoeic word for an evil spirit (*boi) and a baby word for 'brother' (*bo). [Liberman]
A noticable number of the modern words for 'boy', 'girl', and 'child' were originally colloquial nicknames, derogatory or whimsical, in part endearing, and finally commonplace. These, as is natural, are of the most diverse, and in part obscure, origin. [Buck]