weightless

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

Photons have no mass – they are weightless. 光子没有质量——它们是没有重量的。

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. 海伦描述了她身处太空时失重状态下的生活。