leave unchanged or undisturbed or refrain from taking
"leave it as is"
"leave the young fawn alone"
"leave the flowers that you see in the park behind"
To leave alone, let be; to stop bothering.
Much less; to say nothing of; used after one negative clause to introduce another, usually broader and more important clause, whose negation is implied by the negation of the first. However either of these instances mentioned can be applied with the use of let alone.