affidavit
UK[ˌæfɪˈdeɪvɪt]US[ˌæfɪˈdeɪvɪt]
n
A written statement confirmed by oath or affirmation, for use as evidence in court.
Etymology
The word 'affidavit' entered English in the mid-16th century directly from Medieval Latin legal language. It originates from the Latin phrase 'affidavit he', meaning 'he has made an oath', which was the opening word of a sworn statement in medieval legal documents. The core root is Latin 'fides', meaning faith or trust, from the Proto-Indo-European root bʰeydʰ- (to trust, confide, persuade). Thus, the term's literal meaning, 'he has pledged his faith', evolved logically into its modern legal sense of a sworn written testimony, where the declarant pledges their credibility under oath.
Analysis
The word is a simplex loanword from Latin. It is the third person singular perfect indicative form of the Medieval Latin verb 'affidare', meaning 'he/she has pledged upon oath'. The morpheme 'ad-' (to, towards) is fused with 'fidare' (to trust, from 'fides' meaning faith).
Examples
The witness submitted a sworn affidavit detailing what he saw.
The evidence included an affidavit from a forensic expert.
You may need to sign an affidavit confirming your identity and residency.