That annoying visit from your boss to tell you to do something you were about to do. Usually punctuated by your own reminder message popping up on your screen moments after he's left leaving him feeling like you weren't going to do it and you feeling like you're being micro-managed.
Also applies when your girl tells you its her birthday/anniversary/valentines tomorrow when you've actually remembered for a change.
John: Dave came in to tell me to run that revenue report, I do it everyday at four, why would he think I need his preminder?
Doug: Its Sallys birthday next week, she just gave me a preminder even though I've already got her a gift.
Ted really went after it when he ordered 10 Carolina Reaperchicken wings last night. He powered through 6 and then tapped out, though he took the remaining four to-go and finished them later in the eve. The next morning he got the early morning reaper reminder and remained skittish about his PMBM that was coming later that day. The whole experience gave new meaning to heat seat.
A rancid reminder is the act of taking a shit earlier in the day and not flushing it and leaving it there. Once you return to the toilet later on and take a piss on the old shit the smell that is let off is known as a rancid reminder.