Etymology
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woebegone (adj.)
c. 1300, in expressions such as me is wo bigone "woe has beset me," from woe + begon, past participle of Middle English bego "to beset, surround, overwhelm," from Old English began "go over, traverse; inhabit, occupy; encompass, surround" (see be- + go (v.)). The verb is now obsolete, and its only survival is the fossilized past participle in this word.
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lackadaisical (adj.)
"sentimentally woebegone" [Century Dictionary], 1768, lack-adaysical (Sterne), from interjection lackadaisy "alas, alack" (1748), a ludicrous alteration of lack-a-day (1690s), an exclamation of sorrow or regret, from alack the day (1590s). Hence, "given to crying 'lack-a-day,' vapidly sentimental." Sense probably altered by influence of lax. Related: Lackadaisically.
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