countersign

• POS: Noun, Verb (usu participle), Verb (transitive)
• HYPHEN: coun=ter=sign

CIDE DICTIONARY

countersign, v. t. [Counter- + sign: cf. F. contresigner.].

 To sign on the opposite side of (an instrument or writing); hence, to sign in addition to the signature of a principal or superior, in order to attest the authenticity of a writing.  [1913 Webster]

countersign, a. 

•  The signature of a secretary or other officer to a writing signed by a principal or superior, to attest its authenticity.  [1913 Webster]
•  A private signal, word, or phrase, which must be given in order to pass a sentry; a watchword.  [1913 Webster]

OXFORD DICTIONARY

countersign, v. & n.
--v.tr.
1 add a signature to (a document already signed by another).
2 ratify.
--n.
1 a watchword or password spoken to a person on guard (cf. PAROLE).
2 a mark used for identification etc.

Derivative

counter-signature n.

Etymology

F contresigner (v.), contresigne (n.) f. It. contrasegno (as COUNTER-, SIGN)

THESAURUS

countersign

ID card, John Hancock, OK, X, accept, accredit, affirm, amen, approve, assure, authenticate, authorize, autograph, avouch, badge, calligram, calling card, card, certify, christcross, cipher, confirm, cosign, countermark, countersignature, counterstamp, credentials, cross, device, dog tag, endorse, endorsement, give permission, give the go-ahead, give the imprimatur, give thumbs up, guarantee, hand, identification, identification badge, identification tag, initial, initials, letter of introduction, make a promise, mark, mark of signature, monogram, notarize, open sesame, pass, pass on, pass upon, password, permit, pledge, plight, press card, promise, ratify, rubber stamp, sanction, say amen to, seal, second, secret grip, serial number, shibboleth, sigil, sign, sign and seal, sign manual, signature, signet, subscribe to, subscription, support, swear, swear and affirm, swear to, tessera, token, troth, undersign, underwrite, validate, visa, vise, visiting card, vouch, vow, warrant, watchword, word

ROGET THESAURUS

countersign

Security

VB 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.

Evidence

VB be evidence, evince, show, betoken, tell of, indicate, imply, involve, argue, bespeak, breathe, have weight, carry weight, tell, speak volumes, speak for itself, rest upon, depend upon, repose on, bear witness, give evidence, testify, depose, witness, vouch for, sign, seal, undersign, set one's hand and seal, sign and seal, deliver as one's act and deed, certify, attest, acknowledge, make absolute, confirm, prove (demonstrate), indorse, countersign, corroborate, support, ratify, bear out, uphold, warrant, adduce, attest, cite, quote, refer to, appeal to, call, call to witness, bring forward, bring into court, allege, plead, produce witnesses, confront witnesses, place into evidence, mark into evidence, collect evidence, bring together evidence, rake up evidence, experiment, have a case, make out a case, establish, authenticate, substantiate, verify, make good, quote chapter and verse, bring home to, bring to book.

Assent

VB assent, give assent, yield assent, nod assent, acquiesce, agree, receive, accept, accede, accord, concur, lend oneself to, consent, coincide, reciprocate, go with, be at one with, go along with, chime in with, strike in with, close in with, echo, enter into one's views, agree in opinion, vote, give one's voice for, recognize, subscribe to, conform to, defer to, say yes to, say ditto, amen to, say aye to, acknowledge, own, admit, allow, avow, confess, concede, come round to, abide by, permit, arrive at an understanding, come to an understanding, come to terms, come to an agreement, confirm, affirm, ratify, appprove, indorse, countersign, corroborate, go with the stream, swim with the stream, go with the flow, blow with the wind, be in fashion, join in the chorus, join the crowd, be one of the guys, be part of the group, go with the crowd, don't make waves, be in every mouth.

Indication

N indication, symbolism, symbolization, semiology, semiotics, semeiology, semeiotics, Zeitgeist, characteristic, diagnostic, lineament, feature, trait, fingerprint, voiceprint, footprint, noseprint, cloven hoof, footfall, recognition (memory), diagnostic, divining rod, detector, sign, symbol, index, indice, indicator, point, pointer, exponent, note, token, symptom, dollar sign, dollar mark, type, figure, emblem, cipher, device, representation, epigraph, motto, posy, gesture, gesticulation, pantomime, wink, glance, leer, nod, shrug, beck, touch, nudge, dactylology, dactylonomy, freemasonry, telegraphy, chirology, byplay, dumb show, cue, hint, clue, clew, key, scent, signal, signal post, rocket, blue light, watch fire, watch tower, telegraph, semaphore, flagstaff, cresset, fiery cross, calumet, heliograph, guidon, headlight, mark, scratch, line, stroke, dash, score, stripe, streak, tick, dot, point, notch, nick, print, imprint, impress, impression, keyboard symbols, printing symbols, red letter, italics, sublineation, underlining, bold font, jotting, note, annotation, reference, blaze, cedilla, guillemets, hachure, quotation marks, ", double quotes, " ", parentheses, "( )", brackets, "", braces, "", left arrow, "<", right arrow, ">", forward slash, "/", backward slash, "\", exclamation point, "!", commercial at, "@", pound sign, "#", percent sign, "%", carat, "", ampersand, "&", asterisk, "*", hyphen, "-", dash, "-", "_", em dash, "--", plus sign, "+", equals sign, "=", question mark, "?", period, ", ", semicolon, ", ", colon, ":", comma, ", ", apostrophe, "'", single quote, "'", tilde, "~", badge, criterion, countercheck, countermark, countersign, counterfoil, duplicate, tally, label, ticket, billet, letter, counter, check, chip, chop, dib, totem, tessera, card, bill, witness, voucher, stamp, cacher, trade mark, Hall mark, signature, mark, autograph, autography, attestation, hand, hand writing, sign manual, cipher, seal, sigil, signet, hand and seal, paraph, brand, superscription, indorsement, endorsement, password, watchword, catchword, security card, pass, passkey, credentials, open sesame, timbrology, mot de passe, mot du guet, pass-parole, shibboleth, title, heading, docket, address card, visiting card, carte de visite, insignia, banner, banneret, bannerol, bandrol, flag, colors, streamer, standard, eagle, labarum, oriflamb, oriflamme, figurehead, ensign, pennon, pennant, pendant, burgee, blue Peter, jack, ancient, gonfalon, union jack, banderole, old glory, quarantine flag, vexillum, yellow-flag, yellow jack, tricolor, stars and stripes, bunting, heraldry, crest, coat of arms, arms, armorial bearings, hatchment, escutcheon, scutcheon, shield, supporters, livery, uniform, cockade, epaulet, chevron, garland, love knot, favor, beacon, cairn, post, staff, flagstaff, hand, pointer, vane, cock, weathercock, guidepost, handpost, fingerpost, directing post, signpost, pillars of Hercules, pharos, bale-fire, beacon-fire, l'etoile du Nord, landmark, seamark, lighthouse, balize, polestar, loadstar, lodestar, cynosure, guide, address, direction, name, sign, signboard, warning, omen, prefigurement, trace, record, warning &c, alarm, scepter, trophy, gauge, milestone, milepost, brand, fool's cap, check, telltale, test, mileage ticket, milliary, notification, advertisement, word of command, call, bugle call, trumpet call, bell, alarum, cry, battle cry, rallying cry, angelus, reveille, sacring bell, sanctus bell, exposition &c (explanation), proof, pattern, indicating, indicative, indicatory, denotative, connotative, diacritical, representative, typical, symbolic, pantomimic, pathognomonic, symptomatic, characteristic, demonstrative, diagnostic, exponential, emblematic, armorial, individual, known by, recognizable by, indicated, pointed, marked, denotable, indelible, in token of, symbolically, in dumb show, ecce signum, ex ungue leonem, ex pede Herculem, vide ut supra, vultus ariete fortior.