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The anniversary of the date on which best friends officially agreed that they are best friends. Despite the use of the word "bros", this term is not gendered, and is suitable for best friends of any gender. The brosiversary has a set of traditions behind it, but many who celebrate the brosiversary don't follow them. Some examples of the traditional brosiversary gifts are:

1st: A drawing done with your non-dominant hand

2nd: A really cool looking stone you found (you cannot buy it)

3rd: The tiniest sculpture of their favourite animal you can possibly make, in a tiny box (usually a ring box)

4th: A photo of their favourite food, which you should then eat. (the food, not the photograph.)

5th: A high five (it is important to try to make this in person, but if that is entirely impossible, high-fiving a webcam will do)
It's me and my best friend's fifth brosiversary tomorrow! I flew all of the way out here to give them a high-five, as is brosiversary tradition.
by HintHint November 10, 2014
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