The state, quality, or fact of being long. See Usage Note at strength. The measurement of the extent of something along its greatest dimension: the length of the boat. A piece, often of a standard size, that is normally measured along its greatest dimension: a length of cloth. A measure used as a unit to estimate distances: won the race by a length. Extent or distance from beginning to end: the length of a novel; the length of a journey. The amount of time between specified moments; the duration: the length of a meeting. Extent or degree to which an action or policy is carried. Often used in the plural: went to great lengths to prove his point. Linguistics The duration of a vowel. Linguistics The duration of a syllable. The vertical extent of a garment. Often used in combination: knee-length; floor-length. at length After some time; eventually: At length we arrived at our destination. at length For a considerable time; fully: spoke at length about the court ruling.