Nimbostratus is a type of low-level cloud that is thick and often produces steady rain or snow. Some synonyms that can be used to describe this type of cloud include stratus rainclouds, dreary clouds, and overcast clouds. Other descriptive words that can be used to describe nimbostratus clouds include dark, grey, dull, and gloomy. Nimbostratus clouds are often associated with rainy and stormy weather conditions, and can be seen hovering low in the sky. While they may not be the most pleasant sight to behold, they are an important part of the water cycle and help to bring much-needed precipitation to the earth.