Scour
Middle English: from Middle Dutch, Middle Low German schūren, from Old French escurer, from late Latin excurare ‘clean (off)’, from ex- ‘away’ + curare ‘to clean’.
wiktionary
From Middle English scǒuren(“to polish, scour; to clean; to beat, whip”), from Middle Dutch scuren, schuren(“to clean; to polish”) or Middle Low German schǖren, [1] of uncertain origin but probably from Old French escurer, from Medieval Latin scūrō, escūrō, excūrō(“to clean off”), from ex-(“prefix meaning ‘thoroughly’”) + cūrō(“to arrange, see to, take care of”), [2] from cūra(“care, concern”) (from Proto-Indo-European *kʷeys-(“to heed”)) + -ō.
The word is cognate with Danish skure, Middle High German schüren, schiuren (modern German scheuern(“to scour, scrub; to chafe”)), Norwegian skura(“to scrub”), Swedish skura.
From Middle English scǒuren, scure, skoure(“to move quickly; to travel around in search of enemies”), [3] from scǒur(“attack, conflict; pang of emotional suffering”), from Old Norse skýra(“to rush in”) and skúr(“a shower; a shower of missiles”), [4] perhaps influenced by the verb scǒuren: see etymology 1. [3]
etymonline
scour (v.1)
"cleanse by hard rubbing," c. 1200, from Middle Dutch scuren, schuren "to polish, to clean," and from Old French escurer, both from Late Latin excurare "clean off," literally "take good care of," from Latin ex "out" (see ex-) + curare "care for, take care of" (see cure (v.)). Possibly originally a technical term among Flemish workmen in England. Related: Scoured; scouring. As a noun, 1610s, from the verb.
scour (v.2)
"move quickly in search of something," c. 1300, probably from Old Norse skyra "rush in," related to skur "storm, shower, shower of missiles" (see shower (n.)). Perhaps influenced by or blended with Old French escorre "to run out," from Latin excurrere (see excursion). Sense probably influenced by scour (v.1).
