adv. (common).—Half-drunk. For synonyms, see DRINKS and SCREWED.

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  1887.  HAWLEY SMART, Saddle and Sabre, ch. xvii. ‘Black Bill,’ as he was called by his brother jockeys, was very often HALF-COCKED when he got up to ride…. The man could ride as well half-drunk as sober.

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  TO GO OFF AT HALF-COCK (or HALF-COCKED), verb. phr. (sporting).—1.  To fail through hasty and ill-considered endeavours; and 2. (venery) = to ejaculate before completing erection.

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  1848.  J. R. LOWELL, The Biglow Papers [Wk. 1891], p. 231.

        Now don’t GO OFF HALF-COCK: folks never gains
By usin’ pepper-sarse instid o’ brains.

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