Christianity A sin, such as murder or blasphemy, that is so heinous it deprives the soul of sanctifying grace and causes damnation if unpardoned at the time of death.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "mortal sin" in a sentence
"In fact, justfantasizing about their breasts and their other parts the soul-killing mortal sin ofimpure thoughts would also send you straight to hell."
"We are more distinctly conscious that rude penances are out of the question for gentlemen in an enlightened age, and that mortal sin is not incompatible with an appetite for muffins."
"The juridical axiom "honor est in honorante, injuria in injuriato" (honour is measured by the dignity of him who gives it, offence by the dignity of him who receives it) shows that mortal sin bears in a way an infinite malice and that nothing short of a person possessing infinite worth is capable of making full amends for it."