a short pleasure trip, e.g. for sightseeing
(used before a noun) of or offered at a reduced rate for such a trip
an excursion ticket
a deviation from a direct, definite, or proper course; a digression
technical a movement outward and back or from a mean position or axis, or the distance so travelled
excursionist noun
[Latin excursion-, excursio, from excurrere to run out, extend, from ex-1 + currere to run]