unpredictable
1. [ adjective ] impossible to foretell
Related terms: predictable episodic aleatory unforeseeable capricious uncertain
2. [ adjective ] unknown in advance
Examples:

"an unpredictable (or indeterminable) future"

Related terms: indeterminable
3. [ adjective ] not occurring at expected times
Synonyms: irregular
Related terms: sporadic
Similar spelling:   unpredictably
  unpredicted
  unpredictive
  unpreventable
  unpresentable
  unpredictability
  unbridgeable
  unprintable
  unpremeditated
  unprofitable
  unforeseeable
  unprepared
  unprejudiced
  unprofitably
  unprofitableness
  unapparent
  unappareled