agent
(noun)
noun
1. an active and efficient cause; capable of producing a certain effect
- their research uncovered new disease agents
Definition categories: object, cause
2. a representative who acts on behalf of other persons or organizations
Definition categories: person, representative
3. a substance that exerts some force or effect
Definition categories: substance, cause
4. a businessman who buys or sells for another in exchange for a commission
Similar word(s): broker, factor
Definition categories: person, bourgeois, businessperson
5. any agent or representative of a federal agency or bureau
Definition categories: person, functionary, official
6. the semantic role of the animate entity that instigates or causes the happening denoted by the verb in the clause
Definition categories: communication