let alone

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• conjunction idiomatic, negative polarity item 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.
• conjunction idiomatic, rare not to mention, as well as; used after one item, to introduce a further item which is entailed by the first.
• verb transitive To leave alone, let be; to stop bothering.