(archaeology, paleontology) The process by which individuals in a population die off in large numbers as part of a single event (rather than one by one, from a variety of causes).

(archaeology, paleontology) The process by which individuals in a population die off one by one from a variety of causes (rather than in large numbers as part of a single event).

(geography) The total number of deaths in a year among infants under one year of age for every 1,000 live births in a society.

plural of infant mortality rate

The chaos and confusion of life. / The physical body of man (containing the spirit inside).

(Roman Catholicism, theology) A sin which causes the loss of God's grace, leading to eternal damnation, unless the sinner repents, which includes their intent to confess and atone; such a sin is defined as a transgression against one of the Ten Commandments with the full knowledge and deliberate consent of the sinner.

plural of mortal sin

A dangerous and daring jump with possibly lethal outcome. / (figuratively) A risky, dangerous or crucial step or undertaking.

Fighting to the death; a physical fight between persons or groups wherein each side is attempting to kill the other. / (by extension) Any very spirited competition between persons or groups.

plural of mere mortal