Being shocked beyond all reason and no other words that can escape your mouth.

Can be used to express shock, grief, amazement, disbelief, annoyed, etc.
Guy 1: Who is Chuck Norris?
Guy 2: Are you serious?
Guy 1: Yea.
Guy 2: O dear.
by Baron S. July 23, 2009
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when somebody says something so utterly stupid that it simply has to be shouted sarcastically accross the room
aimee: are polar bears made out of fibre-glass?
frank: O DEAR!!!
by Tom Joyce May 18, 2006
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