Delegate (noun)

1. A person chosen or appointed to represent others, especially at a conference.
2. A person authorized to act on behalf of another or others.

Origin:

Late middle english (as a verb in the sense 'send as an envoy'): from latin delegat- 'sent on a commission', from the verb delegare, from de- 'away' + legare 'send'. the noun (late 16th century) is from the verb.

Examples:

1. The company sent a delegate to the trade fair.
2. The delegate was appointed to negotiate the terms of the treaty.
3. The delegate was elected to represent the workers at the meeting.
4. The delegate had the power to vote on behalf of the organization.
5. The delegate reported back to the board on the progress of the negotiations.