The term 'coated with frost' can be described as 'rimed, ' which is a five-letter word. Rime is a type of frost that forms when water droplets in the air freeze onto surfaces. It is most commonly seen on cold winter mornings, when the air is filled with tiny ice crystals that settle on trees, grass, and other objects. Rime is different from hoar frost, which is formed when water vapor in the air condenses directly onto surfaces.