- deadly
- deadly adj1 Deadly, mortal, fatal, lethal mean causing or causative of death.Deadly may imply an extremely high degree of probability rather than a certainty of death; the term therefore applies to something with the capacity of or a marked potentiality for causing death; a deadly disease is one usually ending fatally; a deadly weapon is one capable of inflicting death; the seven deadly sins in theology are those sins which must be avoided because they are the source of other sins and are destructive of spiritual life and progress{
two brave vessels matched in deadly fight, and fighting to the death— Wordsworth
}{poisons more deadly than a mad dog's tooth— Shak.
}{the neglect of form . . . was even deadlier to poetry— Viereck
}Mortal implies that death has occurred or is certain to occur; the term therefore is applicable only to that which actually has caused or is about to cause death; a mortal disease is one that ends fatally; a mortal wound is one that caused or will inevitably cause death; a mortal sin (in contrast with a deadly sin) is a grievous sin deliberately committed and actually inflicting spiritual death. Deadly applies to the instrument that deals the wound or blow that proves mortal{a deadly lance
}{a mortal stab
}{Gigi took off his mask and hid it under a rock; it would be no help to him now, but on the contrary a mortal danger— Upton Sinclair
}Fatal stresses inevitability and applies to a potential or actual result of death, destruction, or disaster. The term is often used in place of mortal as applied to wounds, blows, or illnesses especially when some time has intervened between the wounding or sickening and the dying. Fatal rather than mortal is used in predictions{to remove him to the hospital would be fatal
}{at her age ... it [diabetes] was not speedily or necessarily fatal— Ellis
}{I will not repeat your words . . . because the consequences to you would certainly be fatal— Henry Adams
}Lethal applies only to something which by its very nature is bound to cause death or which exists for the purpose of destroying life{the morphia he gave was a full lethal dose, and presently the body on the deck found peace— Nevil Shute
}{a lethal gas
}{a lethal chamber for the execution of those condemned to death
}{a lethal weapon
}All of these terms except lethal may be used in a lighter sense not implying physical or spiritual death, but something dreaded or greatly feared; a deadly shaft of irony causes complete discomfiture; mortal terror always suggests extreme terror, but only occasionally the terror of losing one's life; a fatal error or a fatal slip may imply the destruction of one's plans or hopes rather than of one's life.Analogous words: destroying or destructive (see DESTROY): killing, slaying (see KILL vb): malignant, malign (see MALICIOUS): baneful, *pernicious: toxic, virulent, *poisonous, pestilential, pestilent: ruinous (see corresponding verb at RUIN)2 Deadly, deathly are frequently confused although in precise use they are not synonyms.Deadly applies to an agent which is bound or extremely likely to cause death (see DEADLY 1); in one of its extended senses, it applies to something which is so implacable or virulent or so relentless that it can result only in death, destruction, or ruin{a deadly enmity existed between them
}{the two railroads are engaged in a deadly conflict over rates
}Deadly may imply no more than an extreme of something{deadly monotony
}{why are you in such deadly haste?
}or it may suggest a disgusting extreme of some depressing or spirit-destroying quality{the city is deadly in summer
}Deathly applies only to that which suggests the appearance or the presence of death{his deathly pallor
}{the deathly stillness of the place
}
New Dictionary of Synonyms. 2014.