動詞 break-down:

1. make a mathematical, chemical, or grammatical analysis of; break down into components or essential features
   同義詞：analyze, analyse, break down, dissect, take apart
2. make ineffective
   同義詞：break down, crush
3. lose control of one's emotions
   同義詞：break down, lose it, snap
4. stop operating or functioning
   同義詞：fail, go bad, give way, die, give out, conk out, go, break, break down
5. separate (substances) into constituent elements or parts
   同義詞：decompose, break up, break down
6. fall apart
   同義詞：crumble, crumple, tumble, break down, collapse
7. cause to fall or collapse
   同義詞：break down
8. collapse due to fatigue, an illness, or a sudden attack
   同義詞：break down, collapse

形容詞 broken-down:

1. in deplorable condition
   同義詞：bedraggled, derelict, dilapidated, ramshackle, tatterdemalion, tumble-down
2. not in working order

bro.ken-down

adj.（形容詞）
Out of working order.
不能用的
In poor condition, as from old age; infirm.
衰老的：處于糟糕狀態(tài)的，如由于年老；虛弱的