c.1200, from Old English cynn "family; race; kind, sort, rank; nature; gender, sex," from Proto-Germanic *kunjam "family" (cf. Old Frisian kenn, Old Saxon kunni, Old Norse kyn, Old High German chunni "kin, race;" Danish and Swedish kön, Middle Dutch, Dutch kunne "sex, gender;" Gothic kuni "family, race," Old Norse kundr "son," German Kind "child"), from PIE *gen(e)- "to produce" (see genus).
diminutive suffix, first attested late 12c. in proper names adopted from Flanders and Holland, probably from Middle Dutch -kin, properly a double-diminutive, from -k + -in. Equivalent to German -chen. Also borrowed in Old French as -quin, where it usually has a bad sense.
This suffix, which is almost barren in French, has been more largely developed in the Picard patois, which uses it for new forms, such as verquin, a shabby little glass (verre); painequin, a bad little loaf (pain); Pierrequin poor little Pierre, &c. ["An Etymological Dictionary of the French Language," transl. G.W. Kitchin, Oxford, 1878]Used in later Middle English with common nouns. In some words it is directly from Dutch or Flemish.