adjuvant
Concise Oxford English Dictionary © 2008 Oxford University Press:
adjuvant /ˈadʒʊv(ə)nt/ Medicine
▶adjective (of therapy) applied after initial treatment for cancer to suppress secondary tumour formation. ▶noun a substance which enhances the body's immune response to an antigen.
– origin C16: from L. adjuvant-, adjuvare, from ad- ‘towards’ + juvare ‘to help’.
'adjuvant' also found in these Oxford entries:

