A Funcle is the act of 2 men fucking the same girl while playing the classic children's test of strength game "Uncle". Hence "Fucking Uncle" or Funcle. It's best played when the woman is on all fours receiving penetration from one player and pleasuring the other orally.
My best friend and I thought with a little luck and a lot of beer we had a good shot at the Funcle with my 2nd cousin, Suzzie.
By Christalle
Funcle
Someone who at first is your uncle and then hooks up with your mom and marries her and becomes your father instead. Combine Father and uncle and you have a funcle. This mostly happens with low income, ignorant redneck families.
Tom said, "My mom is now dating my uncleKenny and they are getting married next month, so I guess that makes him my funcle or step-funcle."