In short, Moore does not simply repeat the contradiction noted above—maintaining that nothing can be substituted for 'good' while simultaneously supplying a synonym for it. He compounds the contradiction by offering several synonyms at once. What makes this error all the more striking is that each of the synonyms he proposes carries a distinct meaning, and none can be analytically reduced to any other without serious distortion of meaning (even if a synthetic connection between them is conceivable). It is rather as though one were to say: 'giraffe' has four synonyms: 'cat', 'leg', 'chair', and 'interest'.

In Chapter 1, Moore once again implicitly equates the concepts of good and duty in responding to an objection. The objection, raised by the hedonist, is that the good may be an "empty shell":
[This is the hedonist speaking]: [...] Most people have used the word [good] for what is pleasant and for what is desired respectively.
[Moore's response:] [...] Nor do I think that [he] would be willing to allow that this was all he meant. They are all so anxious to persuade us that what they call the good is what we really ought to do. Do, pray, act so, because the word good is generally used to denote actions of this nature: such, on this view, would be the substance of their teaching. And in so far as they tell us how we ought to act, their teaching is truly ethical, as they mean it to be ¹.

In other words, the debate between the hedonist and Moore is not merely semantic. They are not simply assigning different content to a word (good) that would otherwise have none. Both implicitly agree that the content of the word 'good' is "what one ought to do" (duty); they differ only on whether the concept of duty can be reduced to that of pleasure, or is independent of it.
In any case, Moore is asserting here, albeit indirectly, that the word 'good'—defined as unanalysable on account of its simplicity—nonetheless contains the concept of duty.

Two further occurrences may be noted, which we shall pass over briefly.

First, in Chapter 2: If [these theories were] true, they would simplify the study of Ethics significantly. They all hold that there is only one kind of fact, of which the existence has any value at all. But they [all consider] that the main reason why the single kind of fact they name […] is that it has been held to define what is meant by good itself ². Moore here acknowledges that "good in itself" is equivalent to "that whose existence has value".

Second, in Chapter V, he argues that in order to determine our duty, we must identify the action in a given situation that produces the most value, both in itself and in its effects—and then, as though these were equivalent, the most good: We must have all this causal knowledge, and further we must know accurately the degree of value both of the action itself and of all these effects
[…] And not only this: we must also possess all this knowledge with regard to the effects of every possible alternative; and must then be able to see by comparison that the total value due to the existence of the action in question will be greater.
But it is obvious that our causal knowledge alone is far too incomplete for us ever to assure ourselves of this result, that an action is our duty: we can never be sure that any action will produce the greatest value possible.
Ethics, therefore, is quite unable to give us a list of duties; but there still remains a humbler task which may be possible for Practical Ethics […] there may be some possibility of shewing which among the alternatives, likely to occur to any one, will produce the greatest sum of good ³.

Here again, then, value, good, and duty are conflated.

1. Ibid., chap. 1, §11
2. Ibid., chap. 2, §24
3. Ibid., chap 5, §91