post·al (pō'stəl)
adj.
Of or relating to a post office or mail service.

idiom:

go postal

1. SlangTo become extremely angry or deranged, especially in an outburst of violence. To become extremely angry or deranged, especially in an outburst of violence.

postally post'al·ly adv.

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The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.

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