noun
one long object; one film or program; one call; one goal or hit
The numeral-counter form for 本: used for long or cylindrical things, and by extension for films, TV programs, phone calls, goals, home runs, and similar countable events.
See also: 本 (ほん)
瓶ビールを一本ください。
Please give me one bottle of beer.
週末に映画を一本見た。
I watched one movie over the weekend.
後で電話を一本入れます。
I'll make one phone call later.
noun
one textual version; one book or manuscript copy; a certain book
Limited use for a single book, manuscript, copy, or version, especially in textual or bibliographic contexts. For an ordinary modern 'one book,' 一冊 is normally the learner-safe choice.
校訂では、別の写本一本を参考にした。
In editing the text, they consulted one other manuscript copy.
結末の違う異本が一本伝わっている。
One variant version with a different ending has been handed down.
noun
ippon; one point; decisive blow
Martial-arts scoring term, especially familiar from judo and kendo. It can refer to a decisive point or to the valid strike or throw that earns it.
決勝戦で、彼は背負い投げで一本を取った。
In the final, he scored an ippon with a shoulder throw.
面に鋭い一本が入った。
A sharp valid strike landed on the head.
noun
Specialized traditional term from the geisha world; rare outside historical, cultural, or hanamachi-related contexts.
See also: 半玉 (はんぎょく)
古い花柳界の言い方で、「一本」は芸者を指すことがある。
In older language of the geisha world, 一本 can refer to a geisha.
noun, used as a suffix
single-minded focus on; devoted solely to
Used after a noun, often in patterns such as 〜一本で and 〜一本に, to mean concentrating on that one thing and not branching out.
彼は野球一本でここまで来た。
He has come this far by devoting himself solely to baseball.
卒業後は研究一本に絞るつもりだ。
After graduation, I intend to focus solely on research.
The counter 本 combines with numerals; 一本 is the special 'one' form, read いっぽん rather than いちほん.
The normal modern counter for one book or bound volume. 一本 for a book is limited and context-dependent.
A general way to say 'one thing.' 一本 is more specific, especially for long objects, media items, calls, scores, and fixed idiomatic uses.
Formed from 一 'one' plus 本, the counter used for long objects and several extended categories. The reading いっぽん reflects the regular sound change from いち + ほん to いっぽん.