From the Latin opacus meaning ‘shady’, a variety of extensive cloud that obscures the Sun or Moon. It is used to describe stratus, stratocumulus, altostratus, and altocumulus. See also cloud classification.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。