Yan, a vassal state of Zhou in present-day Hebei and Liaoning; north Hebei; the four Yan kingdoms of the Sixteen Kingdoms, namely: Former Yan 前燕[Qian2 Yan1] (337-370), Later Yan 後燕|后燕[Hou4 Yan1] (384-409), Southern Yan 南燕[Nan2 Yan1] (398-410), Northern Yan 北燕[Bei3 Yan1] (409-436); surname Yan; swallow (family Hirundinidae); old variant of 宴[yan4]; variant of 燕[yan4]