noun
commentary; annotation; alternative theory
A supplementary explanation or a differing scholarly opinion, often used in academic or critical contexts.
この論文には、著者の余説が付されている。
This paper includes the author's commentary.
古典の注釈書には、さまざまな余説が記されている。
Various alternative theories are recorded in the commentary on the classics.
From 余 (extra, remaining) + 説 (theory, explanation). The exact historical derivation is uncertain, but the compound is used to mean an additional or alternative scholarly opinion.