Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.

Class V. Words Releasing to the Voluntary Powers
Division (I) Individual Volition
Section IV. Antagonism
2. Active Antagonism

709. Coöperation.

   NOUN:COÖPERATION; coadjuvancy, coadjutorship, coadjument [rare], coagency, coefficiency; concert, concurrence, complicity, coadministration, coaction; participation; union [See Junction]; coefficacy; combination [See Combination]; collusion, collusiveness.
  ASSOCIATION, alliance, colleagueship, joint stock, copartnership, pool, gentleman’s agreement; cartel; confederation (party) [See Party]; coalition, federation, fusion; a long pull a strong pull and a pull all together; logrolling [chiefly U. S.], quid pro quo [L.], freemasonry.
  UNANIMITY (assent) [See Assent]; esprit de corps [F.], party spirit; clanship, partisanship; concord [See Concord]; synergy, synergism.
   VERB:COÖPERATE, concur; conduce [See Concurrence]; combine, coadjute, coadjuvate, coact [rare], unite one’s efforts; keep -, draw -, pull -, club -, hand -, hold -, league -, band -, be banded- together; pool; stand -, put- shoulder to shoulder; act in concert, join forces, fraternize, cling to one another; vote solidly, vote in blocks; conspire, concert, lay one’s heads together; confederate, make an agreement with, be in league with; collude, understand one another, play into the hands of, hunt in couples.
  SIDE WITH, take sides with, go along with, go hand in hand with, join hands with, make common cause with, strike in with, unite with, join with, mix oneself up with, take part with, cast in one’s lot with; join -, enter into- partnership with; rally round, flock to, follow the lead of; come to, pass over to, come into the views of; be -, row -, sail- in the same boat; sail on the same tack.
  PARTICIPATE, be a party to, lend oneself to; chip in [colloq.], have a -hand in, – finger in the pie; take -, bear- part in; second (aid) [See Aid]; take the part of, play the game of; espouse a -cause, – quarrel.
   ADJECTIVE:COÖPERATING &c. v.; in coöperation &c. n., in league (party) [See Party]; coadjuvant, coadjutant, coadjutive, coactive, coalitional, hand in glove with; dyed in the wool; synergetic, synergistic.
  FAVORABLE TO [See Aid]; unopposed [See Opposition].
   ADVERB:UNANIMOUSLY, as one man [See Assent]; shoulder to shoulder, in coöperation with.
  1. Due teste valgono piu che una sola.
  2. We must all hang together, or assuredly we shall all hang separately.—Franklin, July 4, 1776
  3. I shall know that your good is mine; ye shall know that my strength is yours.—Kipling