Excursion
late 16th century (in the sense ‘act of running out’, also ‘sortie’ in the phrase alarums and excursions (see alarum): from Latin excursio(n- ), from the verb excurrere ‘run out’, from ex- ‘out’ + currere ‘to run’.
wiktionary
Borrowed from Latin excursio(“a running out, an inroad, invasion, a setting out, beginning of a speech”), from excurrere(“to run out”), from ex(“out”) + currere(“to run”).
etymonline
excursion (n.)
1570s, "a deviation in argument," also "a military sally," from Latin excursionem (nominative excursio) "a running forth, sally, excursion, expedition," figuratively "an outset, opening," noun of action from past-participle stem of excurrere "run out, run forth, hasten forward; project, extend," from ex "out" (see ex-) + currere "to run" (from PIE root *kers- "to run"). Sense of "journey" recorded in English by 1660s.