1. To break down, literally or metaphorically; SYN. fall in, cave in, give, give way, break, founder.
2. To cause to burst; SYN. burst.
3. To fold or close up, as of an umbrella or a music stand.
4. To lose significance, effectiveness, or value.
1. To lose its distinct outline or shape
2. To reduce from a solid to a liquid state, usually by heating; SYN. run, melt down.