An Etymological Dictionary of the German Language/Annotated/kosen
kosen, verb, ‘to chat, caress,’ from Middle High German kôsen, Old High German chôsôn, ‘to converse, talk.’ The meaning of the verb is opposed to any connection with Old High German chôsa, ‘lawsuit,’ and Latin causa, causari, for it nowhere shows an indication of a legal origin; Modern French causer, ‘to chat,’ is also derived from German, since in Latin causa, French chose originated. As a native word kosen (Gothic *kausôn) is of uncertain origin; it is certainly connected, however, with Anglo-Saxon ceást, Middle English cheeste, ‘argument, dispute,’ Dutch keuzelen, ‘to caress.’