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.
(Alternate spelling: neutralise).
1. To make chemically neutral.
2. To make incapable of military action.
3. To make ineffective by counterbalancing the effect of; SYN. nullify.
4. To make politically neutral.