Breakdown

noun

1. A failure, particularly mechanical; something that has failed

   "We saw a breakdown by the side of the road."

2. A physical collapse or lapse of mental stability

   "After so much stress, he suffered a breakdown and simply gave up."

3. Listing, division or categorization in great detail

   "Looking at the breakdown of the budget, I see a few items we could cut."

4. A detailed description of a forthcoming project, including the characters and roles required.
5. Breaking of chemical bonds within a compound to produce simpler compounds or elements.