noun
stark naked body; nude body
Refers to a completely unclothed body; often used in descriptive or formal contexts.
彼は全裸体で湖に飛び込んだ。
He jumped into the lake stark naked.
全裸 is more common and means 'completely naked' as a state, whereas 全裸体 specifically refers to the naked body itself.
Compound of 全 (zen, 'complete') + 裸体 (ratai, 'naked body').