Duck is a term of respect,nothing to do with wild fowl, and hails back to a time when most lands were owned by the duke of devonshire,(Cavendish, shugbourgh hall)and he would be greeted by the locals with a "Good afternoon Duke" and because us stokies only speak the sounds of the words, hey presto Duck...
As ever talking within industry was frowned upon and discouraged,so we learned to say a lot in as short a time as poss,plus the noise in pits Potts etc
yupmeyduc........good afternoon duke
Or, Owat............How are you?
Atginon.......How are you going on?
To which is replied AhOrate..thay!...,...yes alright , and you?
and lastly kin..L...which is left to the imagination to decide based on the previous examples
PS spell cheka didna likit effa