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
at (someone's) service
ready to help someone in any way possible
A member of the hotel staff was at our service during our visit.