In regards to business or personal endeavors: being shady, underhanded, inconsiderate, or sleezy.
Also: not on the up and up.
Antonyms: respectable; considerate; moral; ethical; honest; straightforward
That Walmartish guy down the street keeps letting his dog poop in my yard without cleaning it up.

It was very Walmartish of that guy at the party last night to just take my beer without asking.
by anonymous from walmart land October 27, 2010
Get the Walmartish mug.