Meaning

noun an additive that enhances the effectiveness of medical treatment

adjective furnishing added support

adjective enhancing the action of a medical treatment

originLearned borrowing from Latin adiuvant-, adjuvant- + English -ant (suffix forming adjectives with the sense ‘exhibiting a condition or process’; and forming agent nouns). Adiuvant-, adjuvant- are oblique stems of adiuvāns, adjuvāns (“assisting, helping”), the present active participle of adiuvō (“to assist, help; to be useful; etc.”), from ad- (“prefix meaning ‘to; toward’”) + iuvō (“to aid, help;…

Etymology from Wiktionary, CC BY-SA 3.0