Sloth is one of the seven deadly sins in Catholic teachings. It is the most difficult sin to define and credit as sin, since it refers to an assortment of ideas, dating from antiquity and including mental, spiritual, pathological, and physical states. One definition is a habitual disinclination to exertion, or laziness.
Views concerning the virtue of work to support society and further God's plan suggest that through inactivity, one invites sin: "For Satan finds some mischief still for idle hands to do." ("Against Idleness and Mischief" by Isaac Watts).
The word "sloth" is a translation of the Latin term acedia (Middle English, acciditties) and means "without care". Spiritually, acedia first referred to an affliction to women, religious persons, wherein they became indifferent to their duties and obligations to God. Mentally, acedia has a number of distinctive components of which the most important is affectlessness, a lack of any feeling about self or others, a mind-state that gives rise to boredom, rancor, apathy, and a passive, inert, or sluggish mentation. Physically, acedia is fundamentally a cessation of motion and an indifference to work; it finds expression in [sloth can also be referred as Laziness], idleness, and indolence. Two commentators consider the most accurate translation of acedia to be "self-pity," for it "conveys both the melancholy of the condition and self-centeredness upon which it is founded."
In his Summa Theologica, Saint Thomas Aquinas defined sloth as "sorrow about spiritual good" and as "facetiousness of the mind which neglects to being good... [it] is evil in its effect, if it so oppresses men as to draw him away entirely from good deeds." According to the Catechism of the Catholic Church, "acedia or sloth goes so far as to refuse joy from God and is repelled by goodness".
Sloth ignores the seven gifts of grace given by the Holy Ghost (wisdom, understanding, counsel, knowledge, piety, fortitude, and fear of the Lord); such disregard slows spiritual progress towards life—to neglect manifold duties of charity towards the neighbour, and animosity towards God.