affidavit

The story

1. Proto-Indo-European · derived from*bʰeydʰ-“to command, to persuade, to trust”
2. Medieval Latin · derived fromaffidavit“he has sworn”
3. English todayaffidavit

From Medieval Latin affidavit (“he has sworn”), the third person singular perfect tense of affido (“swear”), from fīdō, ultimately from Proto-Indo-European *bʰeydʰ- (“to command, to persuade, to trust”). Cognate to fidelity and faith (same Latin root), but not to affirm (shared Latin ad- prefix, but different Latin and Proto-Indo-European roots).

Words from the same roots