a comments in this post says
I see no "dot product", which usually refers to vectors. This is a matrix product
which means the term "dot product" is only used for vectors, and the term "matrix product" is only used for matrices.
similarly, square foot (or square meter) is only used to describe an area rather than a distance, strength, or any other topic.
Is there a term/word/phrase to express "only used in a specific topic"?