[For crackt-brain: see next and CRACK- 2.] One having a cracked brain or impaired intellect; a crazy fellow.

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c. 1570.  Marr. Wit & Sc., II. i. in Hazl., Dodsley, II. 334. Such a crackbrain as thou art.

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a. 1661.  Holyday, Juvenal, 91. Sure, once thou wast No Crack-brain.

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1831.  Carlyle, Misc. (1857), II. 329. If the unhappy crackbrain has any handicraft.

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  b.  attrib.

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1718.  Bp. Hutchinson, Witchcraft, Ded. Any crack’d brain Girl.

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1815.  Lamb, Lett. to Southey, in Talfourd II. 10. These crack-brain metaphysics.

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