vouch
/vaʊtʃ/verb
no obj.(vouch for)
1- assert or confirm as a result of one's own experience the truth or accuracy of (something)保证, 担保, 证明：
the explosive used is of my own formulation, and I can vouch for its efficiency.
所用炸药是我自己的配方, 我可以保证其功效。
1.1
- confirm the identity or good character of (someone)确认…的身份; 证明…的人品：
he was refused entrance until someone could vouch for him.
直到有人为他作证, 他方可获准进入。
词源
Middle English （as a legal term in the sense 'summon (a person) to court to prove title to property'）： from Old French voucher 'summon'， based on Latin vocare 'to call'.