four-leaf clover

1. Literally, a clover with four leaves instead of the usual three, traditionally thought to be a good-luck charm due to its rarity. You found a four-leaf clover and you saw a shooting star? Wow, you must be really lucky today! Don't get too excited, it's not a real four-leaf clover—it's just a decoration from St. Patrick's Day. Where do you even find four-leaf clovers? Ireland?

2. By extension, any person or thing that is considered a bringer of good fortune. The new kicker has been something of a four-leaf clover for the team, as they've won every game since he signed with them. No, you can't leave while we're winning! What if you're our four-leaf clover? This jersey is my four-leaf clover. Seriously—the Eagles lose any time I don't wear it during a game!