The Collaborative International Dictionary of English v.0.48:

Coadjutant \Co*ad"ju*tant\, a.
   Mutually assisting or operating; helping. --J. Philips.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Coadjutant \Co*ad"ju*tant\, n.
   An assistant. --R. North.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "coadjutant":
   aid, aide, aide-de-camp, coacting, coactive, coadjutor, coadjuvant,
   coefficient, collaborative, collective, collectivist,
   collectivistic, collusive, combine, combined, commensal, common,
   communal, communalist, communalistic, communist, communistic,
   communitarian, concerted, concordant, concur, concurrent,
   concurring, conjoin, conniving, cooperant, cooperate, cooperating,
   cooperative, ecumenic, fellow, harmonious, harmonized, joint,
   league, lieutenant, mutual, noncompetitive, reciprocal, symbiotic,
   synergetic, synergic, synergistic, uncompetitive