River Cocker NY 158 258 and Cogra Moss NY 095 195

River Cocker NY 158 258  Koker c. 1170, Kok' 1195, Coker  13015

PNCu p9 suggests this is a Celtic name from British *cucrā'.  Ekwall in Place-names of Lancashire notes the same river name as the Cocker in Lancashire, and in Cockerton in Durham (Ekwall, 1922). Ekwall cites Stoke's derivation of the Irish cúar from Celtic *kukrā. The terminal - ā would lower the initial u to o (Jackson, 1953: 573). The meaning would be twisting, winding. In Welsh there is the phrase cogr-droi (GPC), which is also found in mutated form as gogr-droi. The GPC relates to the word to gogr "sieve, strainer", but I think that there was probably an adjective cogr meanining "twisting" from with the Cumbrian Cocker and the others derive.

Related I think is -

Cogra Moss NY 095 195 . I can't find a discussion of this in PNCu. The earliest form of the name is Cogra Moss 1867, but Whaley says the name is obscure (Whaley, 2006). I think this contains a Cumbric name for the Rakegill Beck, namely Cogr with the Norse á "river" added later. The form cogr with /g/ rather than /k/ shows that it was borrowed from Cumbric speakers after the development of /-g-/ in English at the end of the Old English period, the end of the 11th Century. Cocker is borrowed earlier, possibly towards the beginning of Northumbrian control in the 7th Century.