Someplace really far away from you (one of my dad's favorite words). Derived from the actual city of Timbuktu in Mali (or Oregon--your preference). Example: The guy lives in Timbukthree and gues who gets to pick him up?
TIMBUKTHREE
Meaning of TIMBUKTHREE in English
Slang English vocab. Английский сленговый словарь. 2012