Verb
1. provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes;
"His high fever attested to his illness""The buildings in Rome manifest a high level of architectural sophistication""This decision demonstrates his sense of fairness"2. guarantee payment on; of checks
3. authorize officially;
"I am licensed to practice law in this state"4. guarantee as meeting a certain standard;
"certified grade AAA meat"5. declare legally insane