Capable of being predicted or foretold; admitting of prediction, or determination in advance.

adjective. That may be predicted.

adjective. Able to be predicted.

adjective. capable of being foretold

"I don't know what definition of "predictable" they've encountered, but in the one I know, "predictable" is what you were expecting and, when you don't get it, that's "unpredictable"."

unpredictable  

foreseeable  inevitable  

predict  prediction  predictor  

predictability  

unpredictable  

acceptable  bore  coherent  consistent  credible  

anticipatable  anticipated  apt  balanced  calculable