Based on the provided reference, understanding "frost cloud" requires considering both "cloud" and "frost" individually.
A cloud forms when water vapor in the air freezes. Frost is defined as water vapor transforming directly into a solid state due to the cold temperatures. Combining these, we can infer the meaning.
Therefore, a "frost cloud" most likely refers to:
- A cloud that is primarily composed of ice crystals, formed when water vapor freezes directly into ice due to very cold temperatures in the atmosphere. This is analogous to how frost forms on surfaces.
In summary, "frost cloud" describes a cloud mainly containing ice crystals, resulting from frozen water vapor at low temperatures.
