Averment

1. The act of averring, or that which is averred; affirmation; positive assertion.
2. Verification; establishment by evidence.
3. (Law) A positive statement of facts; an allegation; an offer to justify or prove what is alleged.

In any stage of pleadings, when either party advances new matter, he avers it to be true, by using this form of words: “and this he is ready to verify.” This was formerly called an averment. It modern pleading, it is termed a verification. Blackstone.