The Collaborative International Dictionary of English v.0.48:

Teamwork \Team"work`\, n.
   1. Work done by a team, as distinguished from that done by
      personal labor.
      [1913 Webster]

   2. Work done by a number of associates, usually each doing a
      clearly defined portion, but all subordinating personal
      prominence to the efficiency of the whole; as, the
      teamwork of a football eleven or a gun crew.
      [Webster 1913 Suppl.]

            Is the teamwork system employed, or does one workman
            make the whole cigar?                 --U. S.
                                                  Consular
                                                  Repts.
      [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

teamwork
    n 1: cooperative work done by a team (especially when it is
         effective); "it will take money, good planning and, above
         all, teamwork"

Moby Thesaurus II by Grady Ward, 1.0:

61 Moby Thesaurus words for "teamwork":
   bipartisanship, coaction, coadjuvancy, coadministration, coagency,
   cochairmanship, codirectorship, collaboration, collaborativeness,
   collectivism, collusion, commensalism, common effort,
   common enterprise, communalism, communism, communitarianism,
   community, complicity, concert, concord, concordance, concurrence,
   cooperation, cooperativeness, duet, duumvirate, ecumenicalism,
   ecumenicism, ecumenism, esprit, esprit de corps, fellow feeling,
   fellowship, harmony, joining of forces, joint effort,
   joint operation, mass action, morale, mutual assistance, mutualism,
   mutuality, octet, pooling, pooling of resources, pulling together,
   quartet, quintet, reciprocity, septet, sextet, solidarity,
   symbiosis, synergism, synergy, team spirit, trio, triumvirate,
   troika, united action



The Free On-line Dictionary of Computing (30 December 2018):

Teamwork

    A SASD tool from Sterling
   Software, formerly CADRE Technologies, which supports the
   Shlaer/Mellor Object-Oriented method and the
   Yourdon-DeMarco, Hatley-Pirbhai, Constantine and Buhr
   notations.

   Teamwork was abandoned when Computer Associates
   acquired Sterling Software in March 2000.

   (2002-05-29)