moving body
Refers to a physical object in motion, often used in technical or descriptive contexts such as physics, photography, or sports.
The camera's moving-body detection function activated.
Dynamic visual acuity is important for athletes.
動体 means a moving object, the direct opposite of 静物, which is an object at rest.
Compound of 動 (movement) and 体 (body). The exact historical derivation is uncertain, but the meaning is transparent from its components.