na-adjective, noun which may take the genitive case particle 'no', noun
Describes a cold or chilly condition, often used for weather, air, or objects. Can be used as a noun, adjectival noun (na-adjective), or with の.
Today was a cold day.
Vegetables grown in cold regions are sweeter.
Compound of 冷 (rei, 'cold') and 寒 (kan, 'cold'). The exact historical derivation is uncertain, but it is a straightforward Sino-Japanese compound.