-kin Look up -kin at Dictionary.com
diminutive suffix, first attested late 12c. in proper names adopted from Flanders and Holland. As it is not found in Old English it probably is 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.