[1] : The Collaborative International Dictionary of English v.0.48

adjuvant \ad"juvant\, a. l. adjuvans, p. pr. of adjuvare to
   aid: cf. f. adjuvant. see aid.
   helping; helpful; assisting. r. "adjuvant causes."
   --howell.
   1913 webster
see also:
aid 

[2] : The Collaborative International Dictionary of English v.0.48

adjuvant \ad"juvant\ a^d"j-uvant, n. l. adjuvamentum,
   fr. adjuvare to help; ad + juvare to help.
   1. an assistant. r. --yelverton. as
      1913 webster

   2. med. an ingredient in a prescription drug, which aids or
      modifies the action of the principal ingredient. as
      1913 webster

   3. med., immunology a substance that non-specifically
      enhances immune response to an antigen, such as by
      enhancing the production of antibodies. --as
      as

[3] : WordNet (r) 2.0

adjuvant
     adj 1: relating to something that is added but is not essential;
            "an ancillary pump"; "an adjuvant discipline to forms
            of mysticism"; "the mind and emotions are auxilliary
            to each other" syn: accessory, adjunct, ancillary,
             appurtenant, auxiliary, subsidiary
     2: enhancing the action of a medical treatment; "the adjuvant
        action of certain bacteria"
     n : an additive that enhances the effectiveness of medical
         treatment
see also:
accessory adjunct ancillary appurtenant auxiliary subsidiary 

[4] : Moby Thesaurus II by Grady Ward, 1.0

79 moby thesaurus words for "adjuvant":
   accession, accessory, accompaniment, addenda, addendum, additament,
   addition, additive, additory, additum, adjunct, alterative,
   analeptic, ancillary, annex, annexation, appanage, appendage,
   appendant, appurtenance, appurtenant, assistant, assisting,
   attachment, augment, augmentation, auxiliary, carminative, coda,
   collateral, complement, concomitant, continuation, contributory,
   corollary, corrective, counterirritant, curative, emmenagogue,
   expectorant, extension, extrapolation, fixture, fostering, healing,
   helping, hormone, iatric, increase, increment, instrumental,
   maturative, medicative, medicinal, ministerial, ministering,
   ministrant, nurtural, nutricial, offshoot, pendant, reinforcement,
   remedial, restorative, sanative, sanatory, serving, side effect,
   side issue, subservient, subsidiary, supplement, synergistic,
   tailpiece, therapeutic, theriac, undergirding, vasodilator,
   vitamin

Adjuvant >> A Words
Adjuvant, definition of term: Adjuvant
adjuvant_pag1.html