n. The act of running out or forth; hence, deviation from a fixed or usual course; a passing or advancing beyond fixed or usual limits.n. Digression; deviation; a wandering from a subject or main design; an excursus.n. A journey; specifically, a short journey, jaunt, or trip to some point for a special purpose, with the intention of speedy return: as, a pleasure excursion; a scientific excursion.n. A company traveling together for a special purpose; a joint expedition, especially a holiday expedition.n. In physics, a movement of a moving or vibrating body from a mean position: as, the excursion of a planet from the ecliptic, of a satellite from the apparent position of its primary, or of the prong of a tuning-fork.n. In machinery, the range of stroke of any moving part; the travel: as, the excursion of a pistonrod.n. 7. A projecting addition to a building.To make an excursion.