大穴 おおあな
ōana

Noun

1. large hole

Noun

2. big deficit; heavy losses

Noun

3. long-shot win (in horse racing, etc.); big winnings (on a long shot); a killing (made from a bet)

かり競馬 けいばでたまたま大穴 おうあな てたとしましょう。
karini kēbade tamatama ōanao atetato shimashō.
Let's suppose you happen to strike it rich at the races.