Knowedgeability is a measurement which is often used by sociologists and psychoanalyists to determine, on scale of 1-100, the degree to which any given person can be known. Factors that play into a person's knowedgeability include: personality disorders, intellect, predelectation to small talk, physical appearance, self-image, and various other factors which may not be characteristics of the object, but of the subject, which do not explicitly play into the knowedgeability of the object.
Example: Person A is the subject and Person B is the object. Person A has a characteristic which may increase or decrease the knowedgeability of Person B, such as blindness or volume, which may eliminate or alter factors of Person B that play into Person B's knowedgeability. A situation may be as follows: Travis is very handsome, (he has a characteristic which strongly effects his knowedgeability) and Jen is blind. Jen's blindness eliminates Travis' physical appearance from the list of factors which effect his knowedgeability. In this case, Travis' knowedgeability was decreased by Jen's blindness.
This phrase is similar to "already know (something)" or "have known (something) for a long time". It's used when one is too lazy to speak the proper phrase. "Been knowed" seems to have a more powerful meaning though. Like you've known something so long that it's ridiculous that the other person trying to inform you of the topic that it is utterly ridiculous.
I have not yet meetTravis, however I have talk to him on the phone, thus his knowedgeabilityis 3/4. Once I meet Travis his knowedgeability will be at 100%.