A past tense and a past participle of prove.
Having been demonstrated or verified without doubt: "a Soviet leader of proven shrewdness and prescience” ( Joyce Carol Oates). See Usage Note at prove.
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.