The Phrontisery lists "nacarat," which means bright orange-red, "naevus," meaning birthmark, and "nail," which is an old measure of 2 1/4 inches, among several words beginning with the letter N. Writer Robert Beard includes the word "nemesis" as one of the "100 Most Beautiful Words in the English Language" on alphaDictionary.
According to Princeton University, a good word is one recommended by a person as being worthy or desirable. Therefore, a word that qualifies as a good word is a subjective matter and open to differences of opinion.
DailyWritingTips.com includes "nebulous" in a list of beautiful words. Words that sound and look like their definition, according to DailyWritingTips, are a fascinating linguistic feature of English. They can be found in lists that highlight either beautiful or ugly words. Using words like these enriches writing when one chooses words that evoke emotional responses and provide precise connotation.
Inferring that a good word is one that stands out as more special and meaningful than other words from the same text, a beautiful or ugly word can be a good word so long as it is exceptional in its context.