what's meaning of "hat trick'?

what's meaning of "hat trick'? Please Tell me what's the meaning of “Hat-trick”? what's the meaning of " hat trick'? tell me baby? what 's the meaning of. What's the meaning of '@'? what's the meaning of what's the meaning of "Overnight Rate" what's the meaning of this sentence what's the meaning of "china" what's the meaning of love? What's the meaning of nothing? what's the meaning of "single sex"