Webster’s Revised Unabridged Dictionary · 1913
Subject-matter
Sub′ject-mat′ter (·măt′tẽr), n. The matter or thought presented for consideration in some statement or discussion; that which is made the object of thought or study.
As to the subject-matter, words are always to be understood as having a regard thereto. Blackstone.
As science makes progress in any subject-matter, poetry recedes from it. J. H. Newman.