Boredom refers to a certain emptiness of soul or lack of passion; acedia refers to the sadness that comes from our unwillingness to tackle the difficulties involved in attaining something good; laziness more generally refers to the torpor and idleness of one who is not inclined to exert himself. Sloth encompasses all these ideas and more.
In his Pocket Catholic Dictionary, the late Jesuit Fr. John Hardon defined sloth as "sluggishness of soul or boredom because of the exertion necessary for the performance of a good work. The good work may be a corporal task, such as walking; or a mental exercise, such as writing; or a spiritual duty, such as prayer." One might have the impression that sloth is not a typically American sin.
The virtues of diligence and industriousness are deeply ingrained in our nation’s Protestant work ethic. Our youth learn early on that the way to get ahead—at least for those who don’t win the lottery—is by working hard. The early bird catches the worm. Early to bed, early to rise. In a competitive, dog-eat-dog business world, everyone is looking for an "edge," and that typically comes from outworking the competition.
Link (here) to Catholic Answers