Procession
late Old English, via Old French from Latin processio(n- ), from procedere ‘move forward’ (see proceed).
wiktionary
From Middle English processioun, borrowed from Old French pourciession, from Latin prōcessiō(“a marching forward, an advance, in Late Latin a religious procession”), from prōcēdere, past participle prōcessus(“to move forward, advance, proceed”); see proceed.
etymonline
procession (n.)
late Old English, "set of persons walking or riding formally or with ceremonious solemnity; a religious procession; the triumphal entry of Jesus into Jerusalem," from Old French procession "procession" (religious or secular), 11c., and directly from Late Latin processionem (nominative processio) "religious procession," in classical Latin "a marching onward, a going forward, advance," noun of action from past-participle stem of procedere (see proceed). Meaning "act of issuing forth" from anything is late 14c. Related: Processionary.
