Difference between "slap" and spank"

[emsr2d2]

Birthday spanking is a new one on me. In the UK, we have "the bumps" (although that's probably been banned in playgrounds and at parties now by the health and safety brigade). It involved the birthday child being picked up by the arms and legs by a group of people and thrown up in the air (and, ideally, caught!) once for each year.

 

[I_Iliev]

The basic sense of 'spank' that you're referring to relates to a way of hitting someone as a punishment but without causing serious harm.

I talked with a British person living in my country and, like you, he assumes that the basic sense of 'spank' relates to a way of hitting someone usually as a punishment but without causing serious harm.
But in his opinion, the buttocks as a target of the punishment, are also part of the lexical definition of "spank". The buttocks are the normal and usual target for this kind of punishment and "spank" has become linguistically strongly related to that body part. That is why the buttocks are now part of the lexical definition of "spank", and it sounds linquistically natural to use this verb in relation to them.
For some native English speakers, hitting a body part, like the upper part of the back of the thighs, located close to the buttocks can be linguistically defined as "spanking" as well, but on the other hand for most native English speakers, hitting/slapping the font of the thighs or the arms (as a punishment) is not linguistically assumed as "spanking". They would call it slapping/smacking/swatting.

 

[emsr2d2]

All you've done in your last post is re-hash what's been said in the rest of the thread. You haven't asked a follow-up question, nor does it appear you've misunderstood anything.
I stand by what I said at the end of post #18. After 23 posts, it's time to close this thread.

 

[jutfrank]

I could be wrong but I have the impression that the part of the body which is hit/slapped is part of the lexical meaning of the verb "spank"

I meant that it's not part of its denotation.

and according to the dictionaries it is the buttocks (or especially the buttocks).

Yes, you can say that it's especially the buttocks. As I said, think about the agency (the intention) behind the action.

I understand that the punishment without causing serious harm is a key point in the lexical definition of "spank" (and some dictionaries mention it in their definitions) but in this specific definition of the Collins English Dictionary the punishment is not mentioned and the dictionary puts an accent only on the way of hitting and the body part which is hit/slapped.

Yes, they've missed the idea that punishment and/or discipline is a key part of the connotation. Even when spanking is done sexually, that's still a key part of the meaning. The buttocks are relevant only in that that is the area which is most effectively used as a target of the action. Obviously, if you're going to hit a child violently, that's a relatively safe place to do it. And I presume I don't need to explain why it's also this area that's spanked during sexual activity.

Also, there is a ritual called "birthday spanking" which is not a punishment.

I'm not sure what that is exactly, but if it's what I imagine it is, then yes, it is a kind of playful punishment in a sense.

You can slap someone several times on the front of his/her thighs as a punishment without causing a serious harm, but is it a spanking or is it a slapping?

People will think about the back of the legs, not the front. As I said, with 'spank' think about the agency, the intention, the reason behind the action.