Top definition
someone who has the same birthday as you.

whether it be same day, month or year.
Person 1: Hey man It's my birthday.
Person 2: Noway! It's mine too!

Person 1: Hey man, we're birthday twins!
Person 2: Cool man!
by ROCKGODFROMTHE60S January 23, 2016
Get the mug
Get a birthday twin mug for your mama Jovana.