iDirt is any Apple product that you buy that is unnecessary, soon-to-be-obsolete, and is essentially the equivalent of burying your money in the ground.
Consumer #1: I just blew $600 on Apple's latest.
Consumer #2: What did you get this time?
Consumer #3: Oh, just some iDirt for my iTrees.
To erase any evidence of, for the sake of denying any participation in a specific event, or any event, for that matter
Jenny went to my webmail account and found all my e-mail to Candy before I could eRove them.