This was current in the UK's working-class east London/surrounding counties around 1950s & 60s. I haven't heard it used for many years.
It was always used in the sense of the example. I never heard it used as a verb or adjective
Programmer: "sure, I'll get to that right away" ::what the hell, I guess I better do that right away...I'll look up COBB on Urban Dictionary::
Orkin Man: "Mrs, those aren't spider webs; those are surely cob-webs. Your house is infested with nearly extinct Cobs."