A nick name given to the citizens of London, or persons born within the sound of Bow bell, derived from the following story: A citizen of London, being in the country, and hearing a horse neigh, exclaimed, Lord! how that horse laughs! A by-stander telling him that noise was called neighing, the next morning, when the cock crowed, the citizen to shew he had not forgot what was told him, cried out, Do you hear how the cock neighs? The king of the cockneys is mentioned among the regulations for the sports and shows formerly held in the Middle Temple on Childermas Day, where he had his officers, a marshal, constable, butler, &c. See Dugdale’s Origines Juridiciales, p. 247.—Ray says, the interpretation of the word Cockney, is, a young person coaxed or conquered, made wanton; or a nestle cock, delicately bred and brought up, so as, when arrived at man’s estate, to be unable to bear the least hardship. Whatever may be the origin of this appellation, we learn from the following verses, attributed to Hugh Bigot, Earl of Norfolk, that it was in use in the time of king Henry II.
Was I in my castle at Bungay,
Fast by the river Waveney,
I would not care for the king of Cockney;
i.e. the king of London.
Definition taken from The 1811 Dictionary of the Vulgar Tongue, originally by Francis Grose.
Cocker * Cockshut TimeNathan Bailey's 1736 Dictionary of canting and thieving slang
John S. Farmer's collection of canting songs and slang rhymes