"Spank" means "smack".
1) If a child is naughty you would "spank" [smack/hpt] him/her. [Spanking is a *light* hitting.]
Eg. "If you're not careful you will get a spank young lady" = "Behave well or I will [lightly] smack you"
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2) "Spank" can be used to refer to winning a game.
"We're going to spank you at football tomorrow night" = "We're going to beat you at football tomorrow night".
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3+) This one has other (sexual) connotations that I don't want to put on the public forum. If you send me a message I will elaborate... But be careful with this phrase!