Past tense of scrub; cleaned vigorously by rubbing hard. In aerospace, means canceled or postponed (as in a mission launch).
From Middle Dutch 'schrubben' meaning 'to rub hard,' possibly imitative of the sound of scrubbing. The aerospace sense developed in the 1960s space program, metaphorically extending the idea of cleaning to clearing/canceling.
The space program gave 'scrubbed' its most dramatic meaning - when a rocket launch is scrubbed, it transforms from cleaning something dirty to canceling something momentous, showing how technical jargon can completely shift a word's emotional register.
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