weightless

1. ADJ Something that is weightless weighs nothing or seems to weigh nothing. 無重量的; 似無重量的

Photons have no mass – they are weightless. 光子沒有質量——它們是沒有重量的。

2. ADJ A person or object is weightless when they are in space and the Earth's gravity does not affect them, so that they float around. 失重的

Helen described life in a weightless environment during her period in space. 海倫描述了她身処太空時失重狀態下的生活。