The most common meaning given to 雅 is "elegant". I don't know how and why 牙 (teeth) was added to 隹 (short-tailed bird) to form the word but can relate the "short-tailed bird to "elegant".
Most of the Chinese are familiar with two of the short-tailed birds that populated the wild in China - "Crow (烏鴉)" and "Martin (燕子)&...
You have to go back to its original meaning:
陳 is composed of 阝“a row of hills” and 東 “bag tied at both ends; east,” which indicate the original meaning “name of a mound.”
Further meanings are extensions of rebus borrowings, as indicated by Outlier’s meaning tree:
1 (orig.) name of a mound.
2 ○ to exhibit, put on display
3 → to state,...