1. (verb)break down, crush make ineffective "Martin Luther King tried to break down racial discrimination"
2. (verb)analyze, analyse, break down, dissect, take apart make a mathematical, chemical, or grammatical analysis of; breakdown into components or essential features "analyze a specimen"; "analyze a sentence"; "analyze a chemical compound"
3. (verb)break down, lose it, snap lose control of one's emotions "When she heard that she had not passed the exam, she lost it completely"; "When her baby died, she snapped"
4. (verb)fail, go bad, give way, die, give out, conk out, go, break, break down stop operating or functioning "The engine finally went"; "The car died on the road"; "The bus we travelled in broke down on the way to town"; "The coffee maker broke"; "The engine failed on the way to town"; "her eyesight went after the accident"
5. (verb)crumble, crumple, tumble, break down, collapse fall apart "the building crumbled after the explosion"; "Negotiations broke down"