demonstrable
adjective /dɪˈmɒnstrəbl/,  /ˈdemənstrəbl/
  /dɪˈmɑːnstrəbl/
(formal)- that can be shown or proved
- a demonstrable need
 - There is no demonstrable link between the two events.
 
Word Originlate Middle English: from Latin demonstrabilis, from demonstrare ‘point out’.