Actual sin is subdivided, on the basis of its gravity, into mortal and venial. This distinction is often difficult to apply but can hardly be avoided. Amortal sinis a deliberate turning away from God; it is a sin in a grave matter that is committed in full knowledge and with the full...
On the other hand, the perfect cannot become imperfect, by addition; and so a mortal sin cannot become venial, by the addition of a deformity pertaining to the genus of venial sin, for the sin is not diminished if a man commit fornication in order to utter an idle word; rather is it...
"Subject to death," hence "human, of or pertaining to humans" (early 15c.). Also from late 14c. as "implacable, to be satisfied only by death" (of hatreds, enemies, etc.). Meaning "extreme, very great" is from late 14c. Amortal sin(early 15c., opposed tovenial) is one that ...