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5. SI
stands for self-injury. Aka cutting, burning, etc. for emotional distress reasons
Person 1- Did you SI today?

Person 2- I haven't hurt myself on purpose in like a week.
1. SI
Abbr. for 'stupid idiot'
As in Football Factory from 2004:
"Jog on, you si!"
2. SI
Abbr. for "self-injury," also known as self-mutilation. Most common form is cutting, but may also include burning, bruising, skin-picking (excoriation), and other behaviors. There is no single cause for SI. SI is most common in women and tends to persist for years.
As a result of overwhelming anxiety, she turned to SI as a coping mechanism.
by rieux Nov 27, 2003 add a video
3. Si
1. Spanish for "yes".

2. Abbreviation for "suck it!"

3. Abreviatiin for "self injury"
Wy don't u si!
4. Si
An awesome boy that is kind, nice, derpy, hilarious and clumsy and is a wonderful bestfriend.
Is that Si?!
6. si
Short for "System International." Also known as the Metric System.
The SI system makes more sense than the English system. It should be officially adopted by the US, but we Americans are too lazy for change.
by BlastMaster Jun 12, 2003 add a video
7. SI
SI is the abbr. of stupid idiot , although it can also be used in a way in which it means mug
I.E. billy you fucking si, si does not mean sigh which means you bore.
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