Melancholy (noun): a sad mood or feeling (Merriam-Webster)
Found on Page 1, paragraph 6 of “Young Goodman Brown”–> “So they parted; and the young man pursued his way, until, being about to turn the corner by the meeting-house, he looked back and saw the head of Faith still peeping after him, with a melancholy air, in spite of her pink ribbons.”
I believe this word in the quote means that when Mr. Brown looked back to see his wife still watching him, he could see that her countenance was sad. Although Faith was wearing pink flowers, which symbolize life, growth, and happiness, her mood was depressing because Mr. Brown had left to go on his long journey.
