Milo and Tock are properly introduced to Dictionopolis by the king's cabinet members: the Duke of Definition, Minister of Meaning, Earl of Essence, Count of Connotation, and Undersecretary of Understanding.
Usually, a cabinet gives a ruler political and state advice. This cabinet seems to function like a barbershop quintet version of a thesaurus, in fact. Whenever one of them speaks, the others follow. They try to say each idea in as many words and phrases as they can, even telling Milo that "[They're] not interested in making sense; it's not [their] job" (3.60).
Some of their other talents seem pretty obscure, although King Azaz seems to think they're pretty awesome:
"My cabinet members can do all sorts of things. The duke here can make mountains out of molehills. The minister splits hairs. The count makes hay while the sun shines. The earl leaves no stone unturned. And the undersecretary," he finished ominously, "hangs by a thread" (7.27).
Overall, the cabinet helps Milo understand that word choice is important and that the choices themselves are varied. These guys also raise the troubling but interesting idea that "making sense" might not be the most important thing about language. And if nothing else, they sure do offer us a lot of unforgettable puns.