z-cow 

An underachieving person, who by lack of intelligence or lack of motivation, simply believes anything a person says to be true, just because the person says it is true.

Jan is such a z-cow. She actually believed that Paris Hilton was running for president, because John said he saw it on MSNBC.

z-cow by Parkalot January 22, 2008

z-cow 

Anyone who believes something to be true if someone said it was on the internet.

Amy is such a z-cow, after seeing "parkalot" on Myspace she was determined to find the definition.

z-cow by M.C. Chink-a-lot January 23, 2008