ugs. gackeln „(lautmalend)” >
- dt. keckern,
- dt. Küken >engl. chicken ;
- dt. gackeln,
The arrow ">" does not always mean an etymological derivation.
Sometimes it may be just a conjecture (even a refuted one), or an error.
Take the tree as a suggestion for lookup, e.g. try http://etymonline.com/index.php?search=chicken