a slap with the flat of the hand
"The teacher gave the student a firm spank across the palms to correct his behavior."
An instance of spanking, separately or part of a multiple blows-beating; a smack, swat, or slap.
"The teacher gave him a sharp spank on his hand when he threw the ball across the gym."
In plain English: A spank is an informal term for hitting someone lightly with your hand, usually as punishment or playfully between friends.
"The spank was so hard that he cried out in pain immediately after falling down on his butt."
To beat, smack or slap a person's buttocks, with the bare hand or other object, as punishment, gesture, or form of sexual interaction.
"The teacher had to spank the student on his bottom because he was constantly talking out of turn during class."
In plain English: To spank someone is to hit their bottom with your hand as punishment.
"The parent had to spank him for breaking all three windows in his room."
Usage: Use "spank" to describe hitting someone's buttocks with an open hand for discipline or as playful affection rather than using it for general slapping. Avoid confusing this specific action with broader terms like beat when the context involves light punishment or teasing.
Uncertain. Possibly imitative, or perhaps a special use of Etymology 2 (below) in the sense of a horse stamping its foot against the ground. There is no evidence of a relation with Portuguese espancar ("to batter, strike").