provable

Concise Oxford English Dictionary © 2008 Oxford University Press:
prove /pruːv/

▶verb (past part. proved or proven /ˈpruːv(ə)n, ˈprəʊ-/)

• 1 demonstrate by evidence or argument the truth or existence of.

  ■ Law establish the genuineness and validity of (a will).

• 2 show by evidence or argument to be.

  ■ be seen or found to be: the scheme has proved a great success.

  ■ (prove oneself) demonstrate one's abilities or courage.

• 3 subject (a gun) to a testing process.

• 4 (of bread dough) become aerated by the action of yeast; rise.

– phrases
not proven Scots Law a verdict that there is insufficient evidence to establish guilt or innocence.

– derivatives
provability noun,
provable adjective,
provably adverb,
prover noun.

– origin ME: from OFr. prover, from L. probare ‘test, approve, demonstrate’.

usage: Prove has two past participles: proved and proven. Both are correct and can be used more or less interchangeably (this hasn't been proved yet; this hasn't been proven yet). In British English proved is more common, with the exception that proven is always used when the word comes before a noun: a proven talent, not a proved talent.