unpredictable

un- +‎ predictable

unpredictable (comparative more unpredictable, superlative most unpredictable)

1. Unable to be predicted.

   Synonym: (far less common) nonpredictable

   Antonym: predictable

   • 1983, Richard Ellis, The Book of Sharks, Knopf, →ISBN, page 146:

     Sharks are not unpredictable; for the most part, they do exactly what an apex predator is expected to do.

• unpredicted

• unpredictive

unpredictable (plural unpredictables)

1. An unpredictable thing.
   • 1960, United States. Congress. Senate. Committee on Interstate and Foreign Commerce. Subcommittee on Surface Transportation, Motor Vehicle Safety: Hearing..., page 12:

     Other unpredictables, like the recent unexpected blizzards and those of 2 years ago, or a hurricane can cost us many thousands of dollars, and have a severe impact on equipment and facilities.