unknowable
1. [ adjective ] not knowable
Related terms: cognizable
2. [ adjective ] beyond and outside the ordinary range of human experience or understanding
Synonyms: transcendent
Examples:

"philosophers...often explicitly reject the notion of any transcendent reality beyond thought...and claim to be concerned only with thought itself..."- W.P.Alston

Related terms: unknown
Similar spelling:   unknown
  unknowingly
  unsinkable
  unknowingness
  unknowing
  uncombable