1The numeral four, used with the native Japanese counting sequence 一つ, 二つ, 三つ... — a general-purpose way to count four of almost any kind of object.
りんごを四つください。
Please give me four apples.
箱の中にボールが四つ入っている。
There are four balls in the box.
テーブルの上に椅子が四つ並んでいる。
Four chairs are lined up at the table.
その問題は大きく四つに分けて考えられる。
That problem can be broadly divided into four parts.
2A way of saying someone is four years old, typically used for young children.
うちの息子は来月で四つになります。
My son will turn four next month.
「いくつ？」と聞かれて、女の子は「四つ！」と答えた。
When asked, "How old are you?" the little girl answered, "Four!"
あの幼稚園児はまだ四つだ。
That kindergartener is still only four years old.
3A time designation from the old Edo-period time system, corresponding to roughly 10 o'clock. It is not used in modern everyday speech and appears only in period dramas or historical texts.
4A historical slur used to refer to burakumin (a discriminated-against social group), reportedly derived from the idea of four-legged animals. This is a highly offensive term that must never be used in modern speech.
5In sumo, a shortened form of 四つ身 — the state where both wrestlers have grabbed each other's belt with both hands, locked in a cross-grip.
両力士は四つに組んだまま、なかなか決着がつかなかった。
The two wrestlers stayed locked in a cross-grip, and it took a long time to settle the match.
四つに組んだら、腰の使い方が勝敗を分ける。
Once locked in a cross-grip, how you use your hips decides the match.