The story
- Proto-Germanic · inherited from*-ukaz
- Proto-West Germanic · inherited from*-uk
- Old English · inherited from-oc
- Middle English · inherited from-ock
- English today-ock
From Middle English -ock, -ok, -uk, -uck, from Old English -oc, -uc (diminutive suffix), from Proto-West Germanic *-uk, from Proto-Germanic *-ukaz (diminutive suffix). Akin to Old Saxon -ik (diminutive suffix), German -ich, Middle Low German -ken (diminutive suffix), Middle Dutch -kin, Old Norse -kr (diminutive suffix). More at -kin.
Etymology from Wiktionary, CC BY-SA 4.0.