Plural of drat; exclamations of annoyance or irritation; or third-person singular form of the verb 'to drat.'
From 'drat,' which is probably a euphemistic minced oath shortening 'damn' (by removing initial 'd' and final 'mn'). It may also connect to Old English words meaning to grate on one's nerves.
Minced oaths like 'drat' show how language communities create safe ways to express frustration without offending—'drat' worked perfectly in Victorian times when saying 'damn' could get you socially ostracized.
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