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1.
Commonly known as a combination of the words "fraternity" and "castle"; a place where frat daddys abide and are supplied with enough natural light to last all seven years of college. GDIs aren't seen there, but it is common to watch young sorostitues leaving in early hours of the day.
Frat daddy: "Party at the frastle? I'm putting on my sperrys and getting the keys to my tahoe, be there in 5 broski."
by lsufratstar18 March 31, 2010
 
2.
A term used when the Fringe and Castle fandoms mesh together.
Look! There is a picture of Alexis and she looks like a younger Alt!Livia! Frastle!!
or
Walter Bishop is so totally Castle's dad! Frastle!
by Hallow777 March 09, 2011