一徹|いってつittetsu[0]heiban (flat)

1. na-adjective, no-adjectiveobstinate; stubborn; inflexible
   頑固一徹がんこいってつのボスだと思おもっていたけれど、結構けっこうかわいいところもあるじゃない。↗

   I thought our boss was stubborn as a mule but actually he has his cute side.

• Synonym強情ごうじょうNeutralHeadstrong and unyielding by nature, as in 「強情を張る」; 「一徹」 stresses clinging to one thing and never changing.
• Synonym頑固がんこNeutralThe most general word for stubbornness; fits people and hard-to-remove things, as in 「頑固親父」 and 「頑固な汚れ」; 「一徹」 applies only to people.
• Synonym頑強がんきょうNeutralTenacious resistance or holding firm, and also physical sturdiness; it can be used approvingly. 「一徹」 is about a stubborn personality.
• Synonym頑なかたくなWrittenWritten/formal prose: closed-minded and rejecting others' ideas, as in 「頑なに拒む」; stresses the attitude of refusal.
• Synonym意固地いこじNeutralStubbornness out of spite or sulking, as in 「意固地になる」; 「一徹」 is about single-mindedly sticking to one thing to the end.
• Synonym意地っ張りいじっぱりCasualColloquial: competitive and refusing to admit defeat, as in 「意地っ張りな性格」; also names such a person. 「一徹」 is more single-minded.
• Synonym片意地かたいじNeutralPerversely sticking to one's own views and refusing to yield; close to 「意固地」 but rarer — in daily speech say 「意固地」 or 「頑固」.
• Synonym頑迷がんめいWrittenWritten/formal prose: bigoted and unable to see reason, strongly pejorative; 「一徹」 is stubborn but not necessarily blind to reason.
• Related業突く張りごうつくばりCasualColloquial and often abusive: deaf to others' opinions, and can also mean a miser; 「一徹」 carries no hint of stinginess.
• Related固陋ころうWrittenWritten/formal prose: clinging to old ways and rejecting anything new — old-fashioned thinking; 「一徹」 is about a single-minded character.
• Related頑迷固陋がんめいころうWrittenWritten/formal prose four-character idiom for refusing to listen to others, clearly derogatory; 「一徹」 can even carry a touch of admiration.
• Relatedきかぬ気きかぬきCasualRefusing to obey or change one's mind, mostly said of children; 「一徹」 typically describes adults set on their own course.
• Related強情っ張りごうじょうっぱりCasualColloquial: a person with a stubborn streak, or that stubborn nature itself; 「一徹」 stresses sticking to one particular thing.
• Related狷介けんかいWrittenWritten/formal prose: stubborn and aloof, keeping others at a distance out of proud integrity; 「一徹」 implies nothing about being unsociable.
• Related頑固一徹がんこいってつNeutralFour-character idiom: once resolved, stubbornly seeing it through to the end. The closest word to 「一徹」, with stronger force.
• Related偏屈へんくつNeutralA perverse, eccentric and unsociable character, as in 「偏屈な老人」; 「一徹」 means only stubbornness, with no hint of eccentricity.
• Related剛愎ごうふくWrittenWritten/formal prose: wilful and self-assured, ignoring others' advice; 「一徹」 is single-minded but carries no suggestion of arrogance.
• RelatedへんこWrittenWritten/formal prose and rare: narrow-minded and stubborn; in everyday speech use 「頑固」 or 「偏屈」.
• Related情張りじょうはりCasualInsisting on one's own views and refusing to budge; uncommon — 「強情」 or 「意地っ張り」 are the everyday choices.
• Antonym柔軟じゅうなんNeutralFlexible in thinking and adaptable, also physically supple; the opposite of 「一徹」 in whether one's thinking bends.
• Antonym妥協だきょうNeutralCompromising or giving in, as in 「妥協を許さない」; the opposite of 「一徹」's refusal to yield to the very end.

For plain stubbornness use 「頑固」. 「一徹」 is for single-mindedly seeing one thing through, often as 「頑固一徹」 or 「老いの一徹」. Sulky stubbornness is 「意固地」, refusing to admit defeat is 「意地っ張り」, and flexibility is 「柔軟」.

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

1. 一ひとつのことにこだわり、頑固がんこなさま。