unpredictable

1. Not capable of being foretold (synset 301847916)
   also: uncertain - not certain to occur; not inevitable
   similar to:

   • aleatory - dependent on chance
   • capricious, freakish - changeable
   • episodic, occasional - occurring or appearing at usually irregular intervals
   • unforeseeable - incapable of being anticipated
2. Unknown in advance (synset 300743372)
   "an unpredictable (or indeterminable) future"
   similar to: indeterminable, undeterminable - not capable of being definitely decided or ascertained
3. Not occurring at a regular rate or fixed intervals (synset 300596783)
   "an irregular heartbeat"
   similar to: sporadic - recurring in scattered and irregular or unpredictable instances
   same as: irregular

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