noun
one lump; one united body
Almost exclusively used in the phrase 一丸となる or 一丸となって, meaning 'to unite as one' or 'to band together'. Not used as a standalone noun in modern Japanese.
See also: 一丸となって
チームが一丸となって優勝を目指した。
The team united as one and aimed for the championship.
社員全員が一丸となってこの難局を乗り越えよう。
Let's all employees band together and overcome this difficult situation.