adjuvant

Someone who helps or facilitates; an assistant, a helper.

Something that enhances the effectiveness of a medical treatment; a supplementary treatment.

An additive (as in a drug) that aids or modifies the action of the principal ingredient.

(pesticide science) An additive (often a separate product) that enhances the efficacy of pesticide products, but has little or no pesticidal activity itself.

A substance enhancing the immune response to an antigen.

Helping; helpful; assisting.

Designating a supplementary form of treatment, especially a cancer therapy administered after removal of a primary tumour.