To leap forward or upward; spring. To progress by forward leaps or springs. To bounce; rebound. A leap; a jump. A rebound; a bounce. A boundary; a limit. Often used in the plural: Our joy knew no bounds. Your remarks exceed the bounds of reason. The territory on, within, or near limiting lines: the bounds of the kingdom. To set a limit to; confine: a high wall that bounded the prison yard; lives that were bounded by poverty. To constitute the boundary or limit of: a city park that was bounded by busy streets. To identify the boundaries of; demarcate. To border on another place, state, or country. Past tense and past participle of bind. Confined by bonds; tied: bound and gagged hostages. Being under legal or moral obligation: bound by my promise. Equipped with a cover or binding: bound volumes. Predetermined; certain: We're bound to be late. Determined; resolved: She's bound to be mayor. Linguistics Being a form, especially a morpheme, that cannot stand as an independent word, such as a prefix or suffix. Constipated. Headed or intending to head in a specified direction: commuters bound for home; a south-bound train.