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: Imagine yourself trying to stretch (or better yet stand up and do it). Every time you stretch you start to laugh uncontrollably. HA (は) HA HA HA HA HA. Go ahead and laugh like that out loud while you stretch, it will help you to remember this reading.