cold

cold at a low temperature (literally and figuratively, see in cold blood below).
cold comfort poor or inadequate consolation, with reference to a traditional view that charity is often given in a perfunctory or uncaring way. Cold Comfort Farm is the title of a novel (1932) by Stella Gibbons, which depicts the fated, poverty-stricken, and generally uncomfortable rural lives of the Starkadder family and their matriarch, Aunt Ada Doom (see also something nasty in the woodshed); the book was written as a parody of the work of such regional writers as Mary Webb (1881–1927).
cold dark matter matter consisting of massive particles of low energy, which is believed by some scientists to exist in the universe but which has not yet been directly observed.
cold deck in North American usage, a deck of cards which has been dishonestly arranged beforehand.
cold fusion nuclear fusion occurring at or close to room temperature. Claims for its discovery in 1989 are generally held to have been mistaken.
cold hands, warm heart outward signs may contradict the inward reality; saying recorded from the early 20th century.
the cold shoulder a show of intentional unfriendliness; rejection.
cold steel weapons such as swords or knives collectively.
cold turkey the abrupt and complete cessation of taking a drug to which one is addicted; the phrase derives from one of the symptoms, the development of ‘goose-flesh’ on the skin from a sudden chill, caused by this.
Cold War a state of political hostility existing between the Soviet bloc countries and the Western powers after the Second World War, characterized by threats, violent propaganda, subversive activities, and other measures short of open warfare.
in cold blood without feeling or mercy, ruthlessly. According to medieval physiology, blood was naturally hot, so this phrase refers to an unnatural state in which someone can do a (hot-blooded) deed of passion or violence without the normal heating of the blood.
in the cold light of day when one has had time to consider a situation objectively. The idea that ideas and enthusiasms may seem less appealing when examined thus is quite long established; in Thomas Hardy's Jude the Obscure (1895), Sue says ruefully, ‘Things seem so different in the cold light of morning, don't they?’

See also cold enough to freeze the balls off a brass monkey.