So far beyond what is reasonable or decent that it is genuinely shocking. This is a strong, formal word with two closely tied uses. The moral one is the original: an act so wrong that no person with a conscience could do it or defend it — *an unconscionable betrayal*, *it would be unconscionable to leave them with nothing*. The second, now very common, is about sheer excess: *an unconscionable amount of time*, *an unconscionable delay*, *unconscionable prices*. Here the speaker is saying the amount is outrageous, and often stretching the word a bit for effect — some careful writers grumble about that, but it is completely standard now, and you will meet it far more often than the pure moral sense. It also has a precise legal life: in contract law an *unconscionable contract* is one so unfair to one side that a court can refuse to enforce it, usually because one party had far more power or information. That legal use is where the word is sharpest. In tone it is bookish and a little old-fashioned-sounding; in ordinary speech people say *outrageous*, *ridiculous*, or *appalling*. Note the pronunciation: the sc is just an /ʃ/ sound — un-CON-shun-a-bul, four beats after the un.