OK abide by accede accept acclaim accredit acquiesce acquiesce in affirm agree agree to agree with amen applaud approve assent assure attest authenticate authorize autograph back be sponsor for bond buy certify cheer comply confirm consent cosign countersecure countersign endorse ensure give permission give the go-ahead give the imprimatur give the nod give thumbs up guarantee guaranty hail hold with in toto initial insure nod nod assent notarize pass pass on pass upon permit ratify receive rubber stamp sanction say amen to seal second secure sign sign and seal sign for sponsor stand behind stand up for support swear and affirm swear to take kindly to undersign underwrite validate visa vise vote for warrant welcome yes yield assent