From Longman Dictionary of Contemporary Englishleave something aloneleave something alone (also let something alone old-fashioned)TOUCH to stop touching an object or changing somethingLeave those cakes alone. They’re for the guests.leave well (enough) alone (=not change something that is satisfactory)In economic matters, they should leave well alone. →alone
Examples from the Corpus
leave well (enough) alone• If I were you, I would leave well enough alone.• A: No disrespect to your stepson, but I would leave well enough alone.• All in all, I think we'd be well advised to leave well alone.• He was tempted to take the cash; but in the end he decided to leave well alone.• In other words, in economicmatters you ought to leave well enough alone.• Thankfully it's proved far easier to leave well alone.• Two days earlier I'd cancelled an appointment with a psychichealer, thinking perhaps I should leave well enough alone.• If you had left well alone and let me carry on my business I wouldn't be here.• You leave well alone, you've done enough damage.