シリアスshiriasu

1. na-adjective, nounserious
   こんなシリアスな芝居しばいを見みるのは初はじめてで貴重きちょうな経験けいけんができました。↗

   That was the first time I had seen such a serious play so it was a valuable experience.

• Synonym真面目まじめNeutralFor earnest, serious-minded attitudes and proper topics, as in 「真面目な話」; 「シリアス」 more often describes a serious plot or atmosphere.
• Synonym本気ほんきNeutralFor when someone is in earnest, not joking, as in 「本気で怒る」 or 「本気でそう思う」; it turns on whether one truly means it.
• Synonym真摯しんしWrittenWritten word for sincere, earnest conduct, as in 「真摯に受け止める」; it is about how one deals with people and things, while 「シリアス」 is about content or atmosphere.
• Synonym真剣しんけんNeutralFor earnest, fully absorbed attitudes, as in 「真剣な表情」; it is about a person's manner, while 「シリアス」 is about the mood.
• Synonym重大じゅうだいNeutralGrave or important, as in 「重大な問題」; it stresses great impact and is not used of plots or atmosphere.
• Synonym深刻しんこくNeutralFor grave, worsening situations, as in 「深刻な事態」; close to 「シリアス」 in its sense of severity.
• Synonym由々しいゆゆしいWrittenWritten word for grave, alarming situations, as in 「由々しき事態」; it stresses that something is worrying.
• Related一途いちずNeutralSingle-minded or devoted, as in 「一途な恋」; it stresses undivided focus, not a serious mood.
• Related重いおもいNeutralHeavy; also for gloomy moods or weighty topics. 「シリアス」 stresses a serious tone, which need not feel oppressive.
• Related懸命けんめいWrittenWritten word for strenuous effort, as in 「懸命の救助」; it stresses trying hard, not a serious atmosphere.
• Related熱心ねっしんNeutralZealous engagement, as in 「熱心に練習」; it stresses enthusiasm and has nothing to do with seriousness.
• Related一生懸命いっしょうけんめいNeutralEveryday word for giving one's all, as in 「一生懸命働く」; it stresses effort, not seriousness.
• Related一筋ひとすじWrittenWritten word for devoting oneself to one thing, as in 「仕事一筋」; it stresses focus, not seriousness.
• Related厳かおごそかWrittenWritten word for solemn dignity, as in 「厳かな儀式」; mostly describes ceremonies and scenes, and is more solemn than 「シリアス」.
• RelatedひたすらWrittenWritten word for doing one thing to the exclusion of all else, as in 「ひたすら待つ」; usually written in kana; stresses single-minded pursuit.
• Related謹厳きんげんWrittenWritten word for stern, scrupulous character, as in 「謹厳実直」; it applies to people, not plots or atmosphere.
• Related生真面目きまじめNeutralOverserious and inflexible; describes a personality with a slightly negative nuance. Not used of plots or atmosphere.
• RelatedひたむきWrittenWritten word for single-minded devotion, as in 「ひたむきな努力」; it stresses dedication, not seriousness.
• RelatedいかめしいWrittenWritten word for stern, forbidding dignity, as in 「厳めしい顔」; it concerns appearance and presence, not plots.
• AntonymコミカルNeutralLoanword meaning comical; as a tone for a work, it is the opposite of the seriousness of 「シリアス」.
• Antonym軽いかるいNeutralLight or minor, as in 「軽い話」; opposite to the weighty seriousness of 「シリアス」.

Use 「シリアス」 for serious plots and atmosphere, as in 「シリアスな展開」. For earnest attitudes or proper topics pick 「真面目」 or 「真剣」; for grave situations 「深刻」. The others cover dedication and effort (「一生懸命」「熱心」「懸命」「ひたむき」「一途」「一筋」「只管」), overserious character (「生真面目」), solemn dignity (「厳か」「厳めしい」「謹厳」), gravity of matters (「重大」「由々しい」「重い」), sincerity (「真摯」「本気」), with 「コミカル」 and 「軽い」 as the comical, light opposites.

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

1. ふざけたり軽かるくしたりせず、真面目まじめで厳粛げんしゅくな様子ようす。