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:

People surround you. They circle around you, calling you a chicken. "Cacko! (かこ) Cacko! Cacko!" Wait, this isn't the sound a chicken makes, right? You laugh at them, thinking their way of making a chicken noise is weird. Go ahead and join in with them and say "Cacko" with them as well.