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're searching all around for a "sagger" (さが) on your body. This is a flap of skin that is sagging on your body really far, and you probably should get it removed.
I’m searching for my grandmother. She has Alzheimer's and hasn’t come home since yesterday.