How to say "dissertation" in Japanese

• 論説ろんせつCommon
  noun, suru verb, transitive verbCovers a written argument or discourse, especially an editorial-style article; despite the gloss, it is seldom the word you want for an academic dissertation and really refers to argumentative writing.
• 論述ろんじゅつ
  noun, suru verb, transitive verbRefers to setting forth a carefully reasoned logical argument in writing, the act of stating one's case; only marginally 'dissertation', it is best for methodical argumentation rather than the document itself.
• 学位論文がくいろんぶん
  nounThis is the word you want for a dissertation or thesis in the academic sense: the substantial written work submitted to earn a degree at a university.
  最初さいしょに、彼かれは学位がくい論文ろんぶんを完成かんせいさせた。↗

  First, he finished his thesis.

For the academic-sense 'dissertation' use 学位論文; 論説 and 論述 both gloss 'dissertation' but really denote written argument or careful reasoning, so they suit essays and argumentation, not the degree-earning document.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 論説ろんせつarticle
• 論述ろんじゅつstatement (of a carefully reasoned logical argument)
• 学位論文がくいろんぶんthesis