OK, accede to, accept, accredit, affirm, agree to, amen, approve, arm, armor, assure, attest, authenticate, authorize, autograph, avouch, back, back up, be sponsor for, bless, bond, certify, champion, cloak, compass about, confirm, consent to, copyright, cosign, countersecure, countersign, cover, cushion, defend, endorse, ensure, fence, fend, finance, give permission, give the go-ahead, give the imprimatur, give thumbs up, guarantee, guaranty, guard, harbor, haven, indorse, initial, insure, invest in, keep, keep from harm, make a promise, make safe, nestle, notarize, okay, pass, pass on, pass upon, patent, permit, pledge, plight, police, promise, protect, ratify, register, ride shotgun for, rubber stamp, safeguard, sanction, say amen to, screen, seal, second, secure, shelter, shield, shroud, sign, sign and seal, sign for, sponsor, stand behind, stand up for, subscribe to, subsidize, subvene, support, swear, swear and affirm, swear to, troth, undersign, uphold, validate, visa, vise, vouch, vow, warrant
promise, give a promise, undertake, engage, make an engagement, form an engagement, enter into an engagement, enter on an engagement, bind oneself, tie oneself, pledge oneself, commit oneself, take upon oneself, vow, swear, give one's word, pass one's word, pledge one's word, plight one's word, give one's honor, pass one's honor, pledge one's honor, plight one's honor, give credit, pass credit, pledge credit, plight credit, give troth, pass troth, pledge troth, plight troth, betroth, plight faith, assure, warrant, guarantee, covenant, attest, hold out an expectation, contract an obligation, become bound to, become sponsor for, answer for, be answerable for, secure, give security, underwrite
, adjure, administer an oath, put to one's oath, swear a witness.
contract, covenant, agree for, engage, treat, negotiate, stipulate, make terms, bargain, make a bargain, strike a bargain, come to terms, come to an understanding, compromise, set at rest, close, close with, conclude, complete, settle, confirm, ratify, clench, subscribe, underwrite
, endorse, indorse, put the seal to, sign, seal, indent, take one at one's word, bargain by inch of candle.
give security, give bail, give substantial bail, go bail, pawn, impawn, spout, mortgage, hypothecate, impignorate, guarantee, warrant, warrantee, assure, accept, indorse, underwrite
, insure, cosign, countersign, sponsor, cosponsor, execute, stamp, sign, seal, let, sett, grant a lease, take a lease, hold a lease, hold in pledge, lend on security.