A) A nice ass way of saying it gets most of the job done
B) A term used by companies so that they don't get sued when their product doesn't work 100%
C) not quite enough; almost
Dude, it says on the label that this new orange mango-tango blueberry-raspberry slam-a-bam anti-bacterial soap kills 99.9% of germs.
5 hours later...
I have AIDS
by Chernasex April 5, 2006
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something big retailers use when their product(s) aren't 100% because of possible side-effects or holes in the design
and i would not be doing my job if i did not ask what the other 0.1% is for. 99.9% just ain't effective
by your best idiot April 7, 2010
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Almost one hundred percent positive; however still leaving slight room for error.
Guy: You were pretty drunk last night. Did you eat the last frozen pizza?

Roommate: No.

Guy: You sure?

Roommate: (Shrugs) 99.9 anyway
by Ventghal February 27, 2008
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Sometimes people, when expressing how certain they are of something, say they are 99% sure of something. Oftentimes, however, they choose to add validity to their statement by adding 9s behind the decimal place, thinking that will prove their words to be truth beyond belief. We can create a scale of how sure a person actually is based upon the numbers of 9s behind the decimal in their percentage:

99.9% sure: 99.9% is absolutely rock-solid; a person who says they are 99.9% sure of something is presenting insight with undoubtable knowledge of the topic. This information can be counted on.

99.99% sure: 99.99% is still measurably accurate. Usually, 99.99% is reserved for situations in which there still remains room for unexpected events. This information can still be counted on, but watch out.

99.999% sure: 99.999% represents the beginning of a slippery slope of doubt. 99.999% generally is used for opinions or statements that cannot be backed with empirical evidence. Most people who frequently express political beliefs will say they are 99.999% sure of something. Be careful before believing someone who is 99.999% of something.

99.9999% sure: At this point, we cannot be completely sure of how positive someone is of something. If a person says they are 99.9999% sure of something, it is basically a 50/50 situation.

99.99999% sure: If a person says they are 99.99999% sure of something, they genuinely have no fucking clue what they are talking about.
99.9...% Sure:

Connor: I am 99.9% sure that the sun will rise tomorrow.

Daniel: I am 99.99% sure that the next Battlefield game will be kickass.

Evan: I am 99.999% sure that Dirk is a homosexual.

Dirk: I am 99.9999% sure that Evan has been raped in the shower.

Johnny: I am 99.99999% positive that Socialism will prevail.

Rebecca: I am 99.999999% certain that I was a cow yesterday and will be again tomorrow.
by Kickpuncher666 April 25, 2011
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