look up any word, like cunt:
 
1.
Flandreau a phrase; which in the northern part of New York state means to "To Cockblock"

Meaning to prevent someone from scoring sexually.

It's believed that this reference was created in younger schools, so students wouldn't be put into trouble for saying "Cockblock".
Example - Situation (A boy is flirting with a girl, and she is falling for it);

Person 1: *Screams to the Boy* - "Get Some!"
Person 2: *Yells at person 1* - "Dude don't be such a Flandreau"
Person 1: *Screams at the Boy again* "Hey, ya' gonna tap that, ya' gonna tap that?", *Responds to person 2* "That was a Flandreau."
by Eric Calzohu July 13, 2010