Wiktionary
conj. 1 (label en idiomatic negative polarity item) much less; to say nothing of; (non-gloss definition: used after one negative clause to introduce another, usually broader and more important clause, whose negation is implied by the negation of the first.) 2 (label en idiomatic positive polarity item rare) not to mention, as well as; (non-gloss definition: used after one item, to introduce a further item which is entailed by the first.) vb. (label en transitive) To leave alone, let be; to stop bothering.
WordNet
adv. much less; "she can't boil potatoes, let alone cook a meal" [syn: not to mention]
Usage examples of "let alone".
There were many curled darlings displaying their fine forms in the nattiest of uniforms, whose gloss had never suffered from so much as a heavy dew, let alone a rainy day on the march.
She did not intend for either of them to get anywhere near the surface of Novagaia, let alone anywhere near the young Sesquoian woman Melie.
I know some people dread the thought of having to give a presentation in a boardroom, let alone appearing before thousands of people.
True, Skye didn't exactly hide the fact, but I didn't even know my mother knew who he was, let alone that he was gay.
This is blatant nonsense, since a quick glance at any map of the Pacific will suffice to show even the casual observer that there is nothing present in that section of ocean for hundreds of miles in any direction, let alone due south!
That government also had economic clout never in history equaled, let alone surpassed.
I had no wish to pass a night in any city, let alone this one, so I continued on up the street, examining every building I passed with extreme care.
Anyone who was still on his feet after such a blast, let alone operating with his faculties intact—.
Even the old sceptic Confucius had to acknowledge this, although he refused to comment on the supernatural, saying he had enough trouble trying to sort out this world, let alone any others!
I've never known anyone named Bob, let alone Hanoi Bob, and only after an uplink to the library did I discover that Hanoi was a city in Asia.
The pace was relaxed, and the whole ambiance so far away from what she ever imagined being on a spaceship to be like - let alone an alien spaceship - that Nettie found herself leaning back against the cushions and letting her mind drift.
It had become clear that the whole project could never break even - let alone go into profit.
I don't insist that this is a bad thing, but it's a major change from the situation of a generation ago, let alone that of a hundred years in the past.
Mephibaal would not permit any such nonsense, let alone allowing one of his charges to get out of hand to the point of trying to rob the rent-taker.