adverb
single-handedly; alone; by oneself
Emphasizes that one person does something without help, often taking on a task or responsibility entirely by themselves. Commonly used with verbs like 引き受ける, 背負う, or 担う.
彼はそのプロジェクトを一手に引き受けた。
He took on the project single-handedly.
母は家事を一手にこなしている。
My mother handles all the housework by herself.