almost always mispelled as "Sidney", usually redhead, often giggly, fun, happy go lucky, very family oriented, loyal, with bad taste in NHL hockey teams.
This is when you make a conscience decision to use Heinz ketchup as a lubricant and masterbate. You then ejaculate in your own hand and eat it. Your mother's premenstrual fluids can be substituted for Heinz ketchup.
If you ever meet a Sindy in your life, you better keep her close. She's a loyal, smart, kind girl with lots of love. She'll make you laugh, and she can light up a room with her gorgeous smile. She's a brave and outgoing soul with a positive outlook on life. She's an easy-going gal and loves having conversations with anyone. If you ever have the chance to become friends with this one of a kind girl, you better take it.
"wow have you met that girl? She's super sweet and really funny!"
"yes! her name's Sindy, right? I talked to her earlier today!! such a nice person."