n.
1.something clearly established
2.property that your creditor can claim in case you default on your obligation
3.a prisoner who is held by one party to insure that another party will meet specified terms
4.one who provides a warrant or guarantee to another
5.a guarantee that an obligation will be met
Idiom of the Day
sit on one's hands
to do nothing, to fail to help
The manager sat on her hands and refused to do anything about the complaints that she had received.