un ‧ pre ‧ dict ‧ a ‧ ble AC /ˌʌnprɪˈdɪktəb ə l◂/ BrE AmE adjective
[ Word Family: noun : ↑ prediction , ↑ predictability ≠ ↑ unpredictability , ↑ predictor ; adjective : ↑ predictable ≠ ↑ unpredictable , ↑ predictive ; verb : ↑ predict ; adverb : ↑ predictably ≠ ↑ unpredictably ]
1 . changing a lot so it is impossible to know what will happen:
unpredictable weather
the unpredictable nature of language
2 . someone who is unpredictable tends to change their behaviour or ideas suddenly, so that you never know what they are going to do or think
—unpredictably adverb
—unpredictability /ˌʌnprɪdɪktəˈbɪləti, ˌʌnprɪdɪktəˈbɪlɪti/ noun [uncountable]