Going to a large retail outlet with the specific intention of watching or recording acts of domestic violence or child-beatery in the aisles.
Done for amusement in most cases, although walmarting for research purposes is not unheard of.
I went walmarting last night because I was bored. I ended up getting great video and laughing for ages. Soon I'll have enough clips for my 'greatest hits' tape!
To place a paper bag over an unattractive female's head before engaging in sexual intercourse (can be simplified as 'bag it and tag it')
"I don't remember her looking like that on our first date. By our second date I had to Walmart that chick."
"She's got a smokin' body, but her face leaves much to be desired. Eh, I'd Walmart her."