What does affidavit mean?
The definition of affidavit
Af`fi*da”vit, n.
Etym: [LL. affidavit he has made oath, perfect tense of affidare. See Affiance, Affy.] (Law)

A sworn statement in writing; a declaration in writing, signed and made upon oath before an authorized magistrate. Bouvier. Burrill.

Note: It is always made ex parte, and without cross-examination, and in this differs from a deposition. It is also applied to written statements made on affirmation.
Synonyms
— Deposition. See Deposition.