Adjuvant
Part of speech: noun
Definition: A thing which aids or assists; an auxiliary. One who helps or facilitates; an assistant. An additive (as in a drug) that aids or modifies the action of the principal ingredient. Something (as in a method) that enhances the effectiveness of a medical treatment. A substance enhancing the immune response to an antigen.
Part of speech: adjective
Definition: The noun used as a modifier.
Helpful
Part of speech: adjective
Definition: Furnishing help; giving aid; useful.
Example sentence: So, for me the town hall meetings are really an opportunity to engage in two-way dialogue with people, and they've been very helpful.