Lottery
Public Lottery, Lottery Ticket
noun
宝 is a treasure. くじ is a lottery. So if you have a treasure lottery (you win treasure if you win the lottery) then you have yourself a lottery.
たからくじ
The reading uses the 宝 vocab reading, たから.
「妹が宝くじに当たったのよ。」「すごいね！で、いくら？」「一万円。」
"My little sister won the lottery." "Oh cool! How much?" "10,000 yen."
きぼうてきかんそくでは、来年あたりに宝くじに当たるはずです。
It's wishful thinking, but I'll probably win the lottery at some point next year.
父親の秘書が宝くじに当たったんだけど、それをフェイスブックに書いた時に秘書を秘密と書き間違えてしまい、みんなが勘違いしてたくさんおめでとうコメントを残してくれました。
My dad's secretary won the lottery, but I made a spelling mistake when I posted it on Facebook. Secretary was spelled secretly. It confused people and I got a lot of congrats.