Farewell and Hegira

Farewell noun - An expression of good wishes at parting.

Hegira and farewell are semantically related In some cases you can use "Hegira" instead a noun "Farewell".

Hegira noun - The flight of Muhammad from Mecca to Medina in 622 which marked the beginning of the Muslim era; the Muslim calendar begins in that year.

Farewell and hegira are semantically related in departure topic. Sometimes you can use "Farewell" instead a noun "Hegira", if it concerns topics such as leaving.