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2. ummm
The response to a question that you know the answer to but don't want to admit, the response to a question you don't know the answer to or just a response to piss someone off.
"Can you help me reformat my hard drive?", ummm...
1. ummm
usualy said by a bloke when asked a question. any question as a matter of fact.

it can also mean the following:
no
yeah
err no way!
totaly
meh wotever
go away
ummm
*clears thoroat*
Girl: Do you have a crush on me?

Boy: ummm...
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