The problem with the term "blockchain" is its lack of a clear definition. A blockchain in its most basic form is nothing more than a data structure: an inversel

The problem with the term "blockchain" is its lack of a clear definition. A blockchain in its most basic form is nothing more than a data structure: an inversely linked list where each node n (for n > 0) contains a hash of node n-1. Bitcoin, of course, uses and stores this data structure in a certain way, but that was done to solve a very specific problem; it makes little sense for most other applications, and it is not part of what a "blockchain" itself is.