matter of life and death

Something that is gravely serious. This top-secret project is a matter of life and death, so every bit of information in it needs to be accurate. I'm a nurse, so if I make a mistake at my job, it's a matter of life and death.

See also: and, death, life, matter, of

matter of life and death

Cliché an issue of great urgency; an issue that will decide between living and dying. We must find a doctor. It's a matter of life and death. A matter of life and death demands that I return home at once.

See also: and, death, life, matter, of

matter of life and death, a

A very urgent issue, situation, or circumstance. This expression can be used either literally, as in She told the doctor to hurry as it was a matter of life and death, or hyperbolically, as in Don't worry about finishing on time-it's hardly a matter of life and death. First recorded in 1849, it alludes to such urgency that someone's life depends on it. Although a matter of life or death would make more sense, it is rarely put that way.

a matter of life and death

a matter of life or death

COMMON If something is a matter of life and death or a matter of life or death, it is extremely important, often because someone could die or suffer great harm if something is not done. 24-hour care can actually be a matter of life and death for premature babies. Please, keep your voice down and just do what I say. This is a matter of life or death. Note: People say that something is not a matter of life and death to say that it is not very important, especially when someone else is acting as if it is. Well, never mind, John, it's not a matter of life and death. Note: People use life-and-death before nouns to describe a situation that is extremely serious or dangerous. We're dealing with a life-and-death situation here.

See also: and, death, life, matter, of

Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012

a matter of life and death

a matter of vital importance.

See also: and, death, life, matter, of

matter of life and death, a

An issue of vital importance. This term, used since the mid-nineteenth century, makes more sense as a matter of life or death, and indeed it sometimes is so used. An 1837 letter of Dickens states, “It is matter of life or death to us, to know whether you have got Ainsworth’s MS yet.” However, a life-and-death matter appears with equal frequency.