Counter-like noun for a single document, letter, or similar item. Often used with 書類, 手紙, はがき, etc.
Please submit one copy of the application form.
I received one letter from a friend yesterday.
Abbreviation of 一方通行. Used in traffic contexts; may appear on signs or in casual speech.
See also: 一方通行
This road is one-way, so you can't enter.
pure straight; 1-9 straight
Mahjong term: a winning hand with tiles 1 through 9 of the same suit. Abbreviation of 一気通貫. Sometimes written in katakana as イッツー.
See also: 一気通貫 (いっきつうかん)
He won with a pure straight and turned the game around.
I wrote one letter of thanks.
This street will become one-way starting next month.
I won a mangan hand with a pure straight.
Please send one copy of the contract.