1. A phrase that can implicitly mean, "sorry, I'm a dumbfuck," "forget that," or "forget I said that because it's idiotic and incriminating." Often used when the person spoken to has no fuckin' clue what the hell you're talking about.
Idiom: 2. "Don't bother" or "don't trouble yourself, it doesn't matter" or "It's no big deal." 3. "Not to mention, or certainly not." 4. "It's none of your beeswax, don't concern yourself with that."
1. Me: You're so nadia, Nadia. You make my heart race and my head crazy.
Me: Never mind.
2. I was trying to get some help with my cuckoo brain, but never mind, I'll figure it out on my own.
3. I can't talk the talk, never mind walk the walk.
4. Never you mind where I'm going to take a piss.