meaning - Definition of "kissing cousins"— Are the dictionaries wrong/incomplete?

With relatives in the US south, I always thought that the definition of "kissing cousin" was a second cousin (or more distant) whom you could kiss and subsequently marry (FWIW I never did either!).

However, a number of dictionaries have a very different definition: namely, a relation close enough to kiss on meeting (sort of like a hug, I gather). I never heard the term used this way. Is it a recent "invention"?

Example:

kissing cousin
noun
1. A relative close enough to be kissed in salutation, hence anyone with whom a person is fairly intimate:
The two species will often prove to be kissing cousins, for they'll crossbreed.
You guys talk like kissing cousins

TFD and Oxford Dictionaries confirm The Dictionary of American Slang's definition.

The closest reference I found to the idea I mentioned was the discussing of Cousin Marriage in Wikepedia.

Has any else heard the term used to refer to cousins who can be married?

Answer

The term usually means a blood relation who is distant enough that you can fool around with, or indeed even marry / have children with.

Your actual question:

Are the dictionaries wrong/incomplete?

Yes, this is an unusual case where, apparently, all the reference works are just plain wrong.

(Note: the idea that the phrase related to "greeting procedures" is totally nonsensical. The idea of Americans (now or historically) "kissing" in greeting is absurd.)

So, say a child "played doctor" with a full sibling, or a full first cousin. That would be incredibly disturbed and psychologists would be called-in.

But a "kissin' cousin" is a relative - distant enough - where it's NOT a psychological emergency if there is some mild sexual involvement.

The term cheekily suggests the frisson of (very mild) incestuous sexuality.

Like any term, of course, it is used in different ways:

(*) distantly related enough that kids can "play doctor"

(*) distantly related enough that two people can indeed have full unprotected sexual intercourse

(*) distantly related enough that, legally, two people can get married

You need only look at the mentioned Elvis song which has astonishingly sexually raw lyrics.

It - uh - playfully talks about light incest, for an example of the usage of the phrase in question:

https://www.youtube.com/watch?v=hn0EdIy_OhI

Well I've got a gal, she's as cute as she can be
She's a distant cousin.
But she's not too distant with me
We'll kiss all night
I'll squeeze her tight
But we're kissin' cousins
and that's what makes it all right
All right, all right, all right

My God, lyrics were explicit then.