I'm ambiguous about it because I'm describing EY's usage of the word, and he's been ambiguous about it.

I typically adapt my usage to the person who I'm talking to, but the way that I typically define "good" in my own head is: "The subset of my preferences which do not in any way reference myself as a person"...or in other words, the behavior which I would prefer if I cared about everyone equally (If I was not selfish and didn't prefer my in-group).

Under my usage, different people can have different conceptions of good. "Good" is a function of the agent making the judgement.

A pebble-sorter might selfishly want to make every pebble pile themselves, but they also might think that increasing the total number of pebble piles in general is "good". Then, according to the Pebblesorters, a "good" pebble-sorter would put overall-prime-pebble-pile-maximization above their own personal -prime-pebble-pile-productivity. According to the Babyeaters, "good" baby-eater would eat babies indiscriminately, even if they selfishly might want to spare their own. According to humans, Pebble sorter values are alien and baby-eater values are evil.