Is blockchain always "public"? Is the following definition of blockchain by its wikipwdia page correct?

Where it is mentioned:


  A blockchain is a decentralized, distributed and public digital ledger
  ...


Cannot we have a private blockchain? And if so, is the above proposition wrong ? when it says always a blockchain is public.

An example: Consider a company or organization which aims at using (permissioned) blockchain such that it is visible only for its (internal) employees. So, it uses ex. visibility property of blockchain but limited only to internal employees.

Please Note that here the question is NOT if using a permissioned blockchain is logical or not, but also the question is the exact definition of a blockchain. So, according to definition of blockchain in its wikipedia page, a permissioned blockchain is real blockchain?
Ok, you can create your own private blockchain. It will be visible only by yourself. Nobody will not even know about it. I do not see any reason for it, but you can call it "blockchain" if you want. You can call it "my private blockchain" or even give any name for this technology, for example "nsdfuishgreryuiw"