Definitions

Yān
Yan, a vassal state of Zhou in modern Hebei and Liaoning north Hebei the four Yan kingdoms of the Sixteen Kingdoms, namely: Former Yan 前燕 (337-370), Later Yan 後燕|后燕 (384-409), Southern Yan 南燕 (398-410), Northern Yan 北燕 (409-436) surname Yan

yàn
swallow (family Hirundinidae)