What is the Latin word for expedition?

The usual Latin words for “expedition” are expedītiō, proficīscor. The right choice depends on the sense; see the distinctions below.

English → Latin

“expedition” in Latin

expedītiōexpedition, campaign, mission; march; mission: an evangelical campaign in a foreign land.proficīscorto set out, depart, leave

The English word expedition itself goes back to Latin pēs, through expeditio.

Riddle & Arnold A Copious and Critical English–Latin Lexicon, 1864

expedition

Military expedition, expeditio. To go on an expedition, in expeditionem ire; expeditionem suscipere; proficisci (πορεύεσθατ, of soldiers, and of generals with soldiers): copias in expeditionem educere; in bellum proficisci with and without cum copiis (of the general).

Haste, Vid.

Quick answer

What is the Latin word for expedition?: The usual Latin words for “expedition” are expedītiō, proficīscor. The right choice depends on the sense; see the distinctions below.

Entry from J. E. Riddle & T. K. Arnold, A Copious and Critical English–Latin Lexicon (rev. C. Anthon, New York: Harper, 1864), digitised by Fergus J. P. Walsh, CC BY-SA 4.0; Latin markup adapted by latindictionary.co.