Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You haven't learned this reading yet so here's a mnemonic to help you:
You made a regrettable decision. You didn't buy that clock you wanted and now it's been discontinued. The salesperson tells you this and all you can say is, "Oh..." (お) really really quietly. How disappointing.
I lost a precious person.