delegito

A textbook participial nominal. Delegi is to delegate; make the participle passive and past with -it-; add -o to turn it into a person. A delegito is one who has been delegated, and the delegating is finished, which is exactly the state a delegate is in when they walk into the hall. Compare dungito, an employee, built the same way from dungi, to hire.

Line the four participial people up and the system does the work: deleganto is the one doing the sending, delegito the one sent, delegonto someone who will send, delegoto someone about to be sent. English has one word and a lot of context; Esperanto has a suffix slot.

This is also a congress word, and the Esperanto movement uses it constantly. The Universala Kongreso runs on delegitoj from national associations, and the UEA's delegita reto is its network of local contacts. If you go to one, that is the word on your badge. Note that delegi itself has no page here yet; the participle outranked its own verb in the frequency list, which happens more often than you would think.