aver

aver \uh-VUR\, transitive verb:

1. To affirm with confidence; to declare in a positive manner, as in confidence of asserting the truth.
2. (Law) To assert, claim, or declare as a fact.

Between us and the bottom of the sea was less than an inch of wood. And yet, I aver it, and I aver it again, I was unafraid.
-- Jack London, The Sea-Wolf

Although it was not quite true, as he liked to aver, that almost forty years passed between his departure for Germany and his eventual return to Austria, he did not hurry back to Vienna after emigrating to the United States.
-- Patrick McGilligan, Fritz Lang: The Nature of the Beast

Many companies aver that the most expedient path to bigger market share or an expanded product portfolio is through a merger or acquisition.
-- Megan Santosus, "Arranged Marriage", CIO Enterprise, July 15, 1999

Aver is from Old French-Medieval French averer, from Medieval Latin adverare, to confirm as authentic, from Latin ad-, ad- + Medieval Latin verare, from Latin verus, true. Other words deriving from verus are very, which sometimes has the sense of "true"; verify, to prove the truth of; and verdict, a decision or judgment, literally a "true-saying" (verus + dictum, saying).