someday (adv.)youdaoicibaDictYouDict[someday 词源字典]
"at some indefinite date in the future," 1768, from some + day.
MISS SOMEDAY.
Poor Charley wooed, but wooed in vain,
From Monday until Sunday;
Still Cupid whisper'd to the swain
"You'll conquer Betsey Someday."

["The Port Folio," June 1816]
[someday etymology, someday origin, 英语词源]
woo (v.)youdaoicibaDictYouDict
Old English wogian "to woo, court, marry," of uncertain origin and with no known cognates; perhaps related to woh, wog- "bent, inclined," as with affection. Related: Wooed; wooing; wooer.