1. To be unable.
2. To be unsuccessful; SYN. go wrong, miscarry.
3. To become bankrupt or insolvent; fail financially and close.
4. To disappoint, prove undependable to; abandon, forsake; SYN. betray.
5. To fail to do something; leave something undone; SYN. neglect.
6. To fail to get a passing grade; SYN. flunk, bomb, flush it.
7. To fall short in what is expected.
8. To get worse.
9. To judge unacceptable.
10. To prove insufficient; SYN. run out, give out.
11. To stop operating or functioning; SYN. give way, die, give out, conk out, go, break, break down.

1. Failure - usually used in the phrase without fail.
2. A failure (as by a security dealer) to deliver or receive securities within a prescribed period after purchase or sale.