- vouch[vouch 词源字典]
- vouch:  Vouch originally meant ‘call as a witness’; ‘guarantee’ is a 16th-century development. The word was borrowed from Old French voucher ‘summon’, which in turn appears to have evolved from Latin vocāre ‘call’ (source of English vocation, vocative, etc). Anglo-Norman used the Old French infinitive verb as a noun, meaning ‘summons’, from which English gets voucher . Vouchsafe  originated as a compound of vouch ‘guarantee’ and safe.
=> vocation[vouch etymology, vouch origin, 英语词源]
- vouch (v.)
- early 14c., "summon into court to prove a title," from Anglo-French voucher, Old French vocher "to call, summon, invoke, claim," probably from Gallo-Roman *voticare, metathesis of Latin vocitare "to call to, summon insistently," frequentative of Latin vocare "to call, call upon, summon" (see voice (n.)). Meaning "guarantee to be true or accurate" is first attested 1590s. Related: Vouched; vouching.