When you are in class and you are supposed to be filling in the blanks for something like science, but instead you fill them in with the same word over and over again. e.g. Unicorn.

Silliness: the art of being silly
The Earth began 14 Unicorn years ago. The Unicorns then roamed the Unicorn for hundreds of years. Around Unicorn years ago the unicorns took over from the unicorns and the fish started to unicorn. Birds were next as they too unicorned, they went from unicorns to bigger unicorns to even bigger unicorns. The unicorns then ruined the Earth creating lots of unicorn which is damaging our solar unicorn.

Today, I used my extreme silliness to make biology more interesting.
by The Unicorn of Unicornacopia October 7, 2017
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something u say when someone's doing something stupid

made while caming when my friend was closing the tent and couldn't shut it
silly no no stop doing that
by Kelsie April 26, 2005
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ADJ.
1. to act/be goofy

2. to be intoxicated

3. substitution for the word cool, awesome, pimp, sick, hot etc

4. when something is expensive/gaudy/ghetto/hood & stupid to waste your money on, unless you are a rapper and have money to waste.
1. "your little sister is so silly."

2. "went to a bar last night and got silly as fuck"

3. "my chain too silly... my wrist too silly... my ride too silly"
phrase coined in the song "get silly" by VIC feat. soulja boy

"nigga your new kicks are silly"

4. " look at that purple cadillac with gold fucking rims, shits silly."

"that bitch's purse is silly"
by at80 June 19, 2008
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Chaldean or Arabic word for "i just fucked". Usually followed by the word "bro"
Chaldean 1: Silli Broooo!!!!
Chaldean 2: Me too! Erub cuta!!!
by BLGFTW December 18, 2009
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When a male gets an Erection for no reason. It basically means a random boner .
Example: I got a Silly in Math class today thinking about that food I had for dinner last night.
by S dog February 17, 2018
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