What does the postpositive adjective 'proper' mean?

[cappy]

My British friend and I were talking about animals. He said that "A tiger is not a cat proper'
I was confused, so I looked up "proper" on the Free Dictionary. This is what it gives me.

Source: The Free Dictionary
"(immediately postpositive) (of an object, quality, etc) referred to or named specifically so as to exclude anything not directly connected with it: his claim is connected with the deed proper."
I was still confused about the meaning of this word when used as a postpositive adjective. So I dig deeper and found this entry from Collins Dictionary.
Source: Collins Dictionary
"You can add proper after a word to indicate that you are referring to the central and most important part of a place, event, or object and want to distinguish it from other things which are not regarded as being important or central to it."
Example: A distinction must be made between archaeology proper and science-based archaeology.
I still have trouble understanding the postpositive adjective's meaning. I would be glad if someone help explain.

 

[Rover_KE]

Answered here.

Please don't post the same question to different forums simultaneously. Post on one forum only, wait for responses and then, only if you are disappointed with/confused by the responses (or there aren't any), post on another forum and include a link to the first forum thread.

(emsr2d2)

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