懐疑|かいぎkaigi[1]atamadaka (head-high)

1. noun, suru verb, transitive verb, intransitive verbdoubt; skepticism; scepticism; disbelief

• Synonym疑いうたがいNeutralNative word with the widest range, covering both doubt and suspicion, as in 「…の疑いがある」; 「懐疑」 is more literary, an attitude of not readily believing.
• Synonym疑惑ぎわくNeutralDoubt over whether something is true or involves wrongdoing, as in scandals like 「収賄疑惑」; 「懐疑」 is the attitude of not readily believing, without implying misconduct.
• Synonym疑念ぎねんWrittenWritten word for doubts held in the mind, as in 「疑念を抱く」 or 「疑念が残る」; concrete doubting thoughts, whereas 「懐疑」 is an attitude.
• Synonym疑問ぎもんNeutralA question or point one does not understand, or something questionable, as in 「疑問に思う」; 「懐疑」 is the stance of not readily believing.
• Synonym疑義ぎぎWrittenDoubt about meaning or validity, as in 「疑義を呈する」; mostly in formal legal or academic contexts.
• Synonym疑ぎWrittenWritten one-character noun for doubt; rarely stands alone, appearing mainly in compounds; in everyday use say 「疑い」.
• Synonym疑心ぎしんWrittenWritten word for a doubting, suspicious frame of mind, best known from 「疑心暗鬼」; it leans toward suspicious feelings, while 「懐疑」 is reasoned reluctance to believe.
• Related半信半疑はんしんはんぎNeutralHalf believing and half doubting — a state of wavering between the two; 「懐疑」 leans toward disbelief.
• Related不審ふしんNeutralFinding someone or something suspicious or odd, as in 「不審者」 or 「挙動不審」; aimed at concrete people and acts, while 「懐疑」 is an abstract attitude.
• Related猜疑さいぎWrittenWritten word for suspecting others of ulterior motives, usually as 「猜疑心」, with a negative tinge; 「懐疑」 is not necessarily about people.
• Related嫌疑けんぎNeutralSuspicion of a crime or other wrongdoing, as in 「殺人の嫌疑」 or 「嫌疑をかけられる」; 「懐疑」 has nothing to do with guilt.
• Related怪訝けげんWrittenLiterary na-adjective for looking or feeling puzzled because the reason is unclear, as in 「怪訝な顔」 or 「怪訝に思う」; 「懐疑」 is an attitude of not readily believing.
• Related狐疑こぎWrittenDoubt coupled with hesitation; rare in writing — in daily speech say 「疑う」 or 「ためらう」; 「懐疑」 carries no nuance of hesitating.
• Related懐疑心かいぎしんNeutralA skeptical state of mind, as in 「懐疑心が強い」; identical in sense to 「懐疑」 but stresses the personal disposition.
• Antonym確信かくしんNeutralFirm belief with no room for doubt and complete confidence — the opposite of 「懐疑」, which withholds trust.
• Antonym信頼しんらいNeutralTrusting and relying on someone, as in 「信頼できる人」 — the opposite of 「懐疑」's refusal to believe easily.

Use 「懐疑」 for an attitude of not readily believing something's truth or value, as in 「懐疑的」. For everyday doubt pick 「疑い」, for open questions 「疑問」, and for suspected wrongdoing 「疑惑」 or 「嫌疑」. The opposite is 「確信」 or 「信頼」.

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

1. 疑うたがいを抱いだくこと。