a short trip or outing to some place, usually for a special purpose and with the intention of a prompt return: a pleasure excursion; a scientific excursion.
a trip on a train, ship, etc., at a reduced rate: weekend excursions to mountain resorts.
the group of persons making such a journey: an excursion of tourists.
a deviation or digression: excursions into futile philosophizing.
Physics. the displacement of a body or a point from a mean position or neutral value, as in an oscillation.