(adj) capable of being demonstrated or proved; ; ; - Walter Bagehot, Syn. provable, Example:obvious lies; a demonstrable lack of concern for the general welfare; practical truth provable to all men
The Collaborative International Dictionary of English (GCIDE) v.0.53 Collaborative International Dictionary (GCIDE)
a. [ L. demonstrabilis: cf. OF. demonstrable, F. démontrable. ] 1. Capable of being demonstrated; that can be proved beyond doubt or question. [ 1913 Webster ]
The grand articles of our belief are as demonstrable as geometry. Glanvill. [ 1913 Webster ]