説(せつ) せつ noun theory, opinion, view 1. theory, hypothesis An explanation or proposed explanation for something, often in academic or scientific contexts. 進化論(しんかろん)はダーウィンが唱(とな)えた説(せつ)だ。 The theory of evolution is a theory proposed by Darwin. いろいろな説(せつ)があるが、真実(しんじつ)はまだわからない。 There are various theories, but the truth is still unknown. 新(あたら)しい説(せつ)が発表(はっぴょう)された。 A new theory was announced. 2. opinion, view A particular viewpoint or belief held by someone. 彼(かれ)の説(せつ)によると、地球(ちきゅう)は温暖化(おんだんか)している。 According to his view, the Earth is warming. 彼女(かのじょ)の説(せつ)では、原因(げんいん)は別(べつ)にある。 According to her view, the cause lies elsewhere. 専門家(せんもんか)の間(あいだ)でも説(せつ)が分(わ)かれている。 Even among experts, opinions are divided. 説(せつ) is used for theories, hypotheses, and opinions. It often appears in compounds and with particles.COMMON PATTERNS:〜という説(せつ): the theory that ~説(せつ)を唱(とな)える: to propose/advocate a theory説(せつ)によると: according to the theory/view〜説(せつ): ~ theory (suffix)COMMON COMPOUNDS:仮説(かせつ): hypothesis学説(がくせつ): academic theory定説(ていせつ): established theory異説(いせつ): different/dissenting opinion俗説(ぞくせつ): popular belief, folk theory general Added 2026.1.13 8:49 · Revised 2026.5.11 5:13 00000/00360_setsu