The Collaborative International Dictionary of English v.0.48:
Provable \Prov"a*ble\, a. [See Prove, and cf. Probable.] Capable of being proved; demonstrable. -- Prov"a*ble*ness, n. -- Prov"a*bly, adv. [1913 Webster] ProvandWordNet (r) 3.0 (2006):
provable adj 1: capable of being demonstrated or proved; "obvious lies"; "a demonstrable lack of concern for the general welfare"; "practical truth provable to all men"- Walter Bagehot [syn: demonstrable, provable]