Definition of averred:
(v) :
(ambitransitive) To assert the truth of (something); to affirm (something) with confidence; to declare (something) in a positive manner.
(v) :
(ambitransitive, law) To justify or prove (an allegation or plea that one has made).
(v) :
(transitive, obsolete) To avouch, prove, or verify the existence or happening of (something), or to offer to do so.
(n) :
(British, dialectal, archaic) A beast of burden; chiefly a workhorse, but also a working ox or other animal.
(n) :
(Northern England, Scotland, dialectal, archaic) An old, useless horse; a nag.