不思議|ふしぎfushigi[0]heiban (flat)

1. na-adjective, nounwonderful; marvelous; strange; incredible; amazing; curious; miraculous; mysterious
   この刀かたなには不思議ふしぎないわれがある。↗

   This sword has a strange history.
2. adverb (with と)strangely enough; oddly enough; for some reason; curiously

• Synonym不可思議ふかしぎWrittenA written, emphatic form of 「不思議」 for something unfathomable and beyond understanding; also the name of a huge number unit.
• Synonym奇怪きかいWrittenWritten word for something bizarre and suspicious, as in 「奇怪な事件」; carries an unsettling, eerie feel, stronger than 「不思議」.
• Synonym奇妙きみょうNeutralRefers to something odd and unlike the norm, as in 「奇妙な形」; stresses the strangeness of appearance or phenomena, while 「不思議」 stresses the inexplicable.
• Synonym珍妙ちんみょうNeutralMeans odd in a rare and comical way, as in 「珍妙な格好」; carries a laughable nuance.
• SynonymミステリアスNeutralLoanword meaning inscrutably mysterious; mostly describes people or atmospheres, as in 「ミステリアスな女性」.
• Synonym神秘しんぴNeutralRefers to mysteries beyond human intellect, as in 「自然の神秘」; carries a solemn, awe-inspired feel.
• Synonym奇異きいWrittenWritten word for something peculiar and abnormal, as in 「奇異な目で見る」; often carries the nuance of a strange gaze.
• SynonymミステリーNeutralLoanword for a mystery or something unexplained; also means detective fiction. Used as a noun.
• Synonym神秘的しんぴてきNeutralMeans mysterious or mystical, as in 「神秘的な雰囲気」; modifies atmospheres and scenery.
• Synonym怪奇かいきNeutralMeans bizarre and eerie; often used for horror material, as in 「怪奇現象」.
• Synonym不可解ふかかいNeutralMeans incomprehensible, as in 「不可解な行動」; stresses intellectual failure to understand.
• Synonym変へんNeutralColloquial word for strange or off, as in 「変な味」; carries negative judgment, while 「不思議」 is neutral puzzlement.
• Synonym妙みょうNeutralMeans strange or odd, as in 「妙な気分」; can also mean skillful or excellent.
• Synonym怪かいWrittenWritten word for strange, eerie things; mostly seen in compounds like 「怪談」 and 「怪物」, rarely used alone.
• Synonym奇々怪々ききかいかいWrittenEmphasizes something extremely bizarre, as in 「奇々怪々な出来事」; has an exaggerated, hyperbolic tone.
• Synonym怪異かいいWrittenWritten word for eerie phenomena or monsters and ghosts; mostly used in ghost stories.
• RelatedおかしいNeutralMeans funny or amusing, or that something is off, as in 「様子がおかしい」; common in speech, often with suspicion.
• Related変わったかわったNeutralMeans unusual or out of the ordinary, as in 「変わった人」; a fairly neutral description, not necessarily inexplicable.
• Related異様いようNeutralMeans abnormal and unsettling, as in 「異様な光景」; carries a sense of unease.
• Related新奇しんきWrittenWritten word for novel and original ideas, as in 「新奇な趣向」; stresses newness and rarity.
• Related怪しいあやしいNeutralMeans suspicious or unreliable, as in 「怪しい人」; implies doubt and wariness, while 「不思議」 is just puzzling.
• Related風変わりふうがわりNeutralMeans eccentric or unconventional in style, as in 「風変わりな人」; mostly for the look or manner of people and things.
• Related珍奇ちんきWrittenWritten word for rare and curious things, as in 「珍奇な動物」; the emphasis is on rarity.
• RelatedけったいCasualKansai dialect for odd or strange, as in 「けったいな人」; has a slangy, folksy flavor.
• Related突飛とっぴNeutralMeans wildly unexpected or offbeat, as in 「突飛な発想」; mostly describes ideas and behavior.
• Related面妖めんようWrittenAn old-fashioned word for strange and inexplicable; today mostly in period dramas or used jokingly.
• Antonym当然とうぜんNeutralAntonym: means natural and to be expected, the opposite of the puzzling 「不思議」.
• Antonym当たり前あたりまえNeutralColloquial antonym: natural, ordinary, taken for granted — the opposite of 「不思議」.
• Antonym普通ふつうNeutralAntonym: normal and ordinary, the opposite of the unusual 「不思議」.

Default to 「不思議」 for what you cannot explain or figure out. Say 「奇妙」 for odd appearance or phenomena, 「怪しい」 when suspicion is involved, 「変」 in casual speech, 「神秘」 for awe-inspiring mystery, and 「不可解」 for what reason cannot grasp; the opposite is 「当たり前」. Other shades: 「珍妙」 comical, 「変わった」 simply unusual, 「ミステリアス」 for people or moods, 「怪異」/「怪奇」 eerie, and written forms like 「不可思議」 or 「奇異」 for formal prose.

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

1. (不可思議ふかしぎの略りゃくか？)不可解ふかかいなこと、合理的ごうりてきに解釈かいしゃくがつかないこと、理解りかいできないこと。