Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you:

You have to remember the あ part but let's include the う as well for this one. Who do you want to meet more than anyone? Think about it. Then, imagine meeting them. The first thing they do is grab your arm and pinch it. You yell out "OW!" (あう) and they laugh and run away.