The Macquarie Dictionary Online [ at 7 March 2010] relevantly defines:
(a) the verb 'represent' to mean '3. to stand or act in the place of, as a substitute, proxy, or agent. 4. to speak and act for by delegated authority: to represent one's government in a foreign country';
(b) the noun 'representation' to mean '1. the act of representing. 4. speech or action on behalf of a person, body, business house, district, or the like by an agent, deputy or representative';
(c) the adjective 'representative' to mean '1. serving to represent; representing. 2. standing or acting for another or others'; and
(d) the noun 'representative' to mean '7. someone or something that represents another or others. 10. an agent or deputy; a legal representative'.
The Oxford English Dictionary Online [ at 7 March 2010] defines:
(a) the verb 'represent' to mean '1. a. To assume or occupy the role or functions of (a person), typically in restricted, and usually formal situations; to be entitled to speak or act on behalf of (a person, group, organization, etc.); (in later use esp.) to act or serve as the spokesperson or advocate of ... b. Originally: to occupy or assume (the status, role, etc.) of a person or group of people (obs.). In later use: to serve as a representative of (the interests, etc.) of a person or group';
(b) the noun 'representation' to mean '3. a. The fact or process of standing for, or in the place of, a person, group, institution, etc., esp. with the right or authority to speak or act on behalf of these; (in later use also) the action or fact of representing a party in a legal case';
(c) the adjective 'representative' to mean '1. a. That stands in the place of a person or thing; spec. ...(b) that speaks or acts on behalf of a wider body or group of people... b. Of, relating to, or based on the fact of one person, group, or thing standing in the place of another ...';
(d) the noun 'representative' to mean '3. a. More generally: a person who stands for, speaks, or acts on behalf of another person or group of people, typically in an official capacity...'