Vouch for, with "to" (6)
I believe the answer is:
attest
(Other definitions for attest that I've seen before include "Adjure" , "Demonstrate" , "University town" , "Corroborate" , "Provide proof of, declare to be true (6)" .)
I believe the answer is:
attest
(Other definitions for attest that I've seen before include "Adjure" , "Demonstrate" , "University town" , "Corroborate" , "Provide proof of, declare to be true (6)" .)