To discribe something or someone that has it all, such as an attractive woman who has all the right parts, a guy who is well built and/or has money or nice things or a sharp car. Refering to the fact that you can get almost anything at Wal-mart.
Hey man, did you see that fine lady over there? She is straight Wal-mart.
Joe is totally Wal-mart. He's good looking, got a good job, a nice car and a fine girlfriend.
Look at the rims on that Impala, and that bad ass paint job. That car is Wal-mart.