cosign

sign

authenticate autograph notarize subscribe superscribe undersign underwrite

add one's name to put John Hancock on put signature on rubber-stamp say amen to sign off on sign on dotted line

censure disapprove oppose protest reject repel unauthorize

assure ensure insure maintain protect prove secure support

affirm angel attest aver back bankroll certify confirm endorse evidence evince grubstake guaranty juice mortgage reassure stake swear testify wager warrant witness

answer for be surety for bind oneself get behind give bond make bail make certain make sure pick up the check pick up the tab sign for stand behind stand up for vouch for

harm hurt injure let go neglect

contradict deny discourage disprove invalidate oppose refute reject repudiate veto

break

underwrite

accede acquiesce advocate approve assent autograph back bless boost consent countenance ditto endorse favor ink obey okay sanction sign support take undersign

get behind give stamp of approval give the go-ahead go along with hold with put John Hancock on rubber-stamp signature yes

condemn deny disagree disallow disapprove discourage dissent hinder hurt object oppose prevent protest refuse reject veto

affirm assert asseverate assure avert avow back certify confirm contend corroborate declare guarantee maintain okay predicate profess prove sponsor substantiate support testify uphold verify vow warrant witness

act as a witness answer for attest to be responsible for bear testimony get behind give an affidavit put forth rubber-stamp say so sign for stand up for swear to swear up and down

break condemn contradict deny desert disapprove disavow disclaim discourage discredit disprove invalidate neglect oppose refuse refute reject repudiate veto

renounce