Hijra

Hijra, as an Arabic word meaning migration (also romanised as hijrah, hejira and hegira) (cf. Hebrew הגירה hagirah for emigration) could mean:

The Hijra (Islam) (هِجْرَةٌ) is the emigration of Muhammad and his followers to the city of Medina in 622, marking the first year of the Islamic calendar, 1 AH (anno higirae).
Migration to Abyssinia, in 615 CE a number of Sahaba migrated to Ethiopia
Meccan boycott of Hashemites and Muhammad, the second migration due to the boycott in 617–619
Migration to Medina, the third and final emigration of Muhammad and his followers to the city of Medina in 622
Hijri year, marks the start of the Hijri year of the Islamic calendar

Hijra may also mean:
Hijra (South Asia), a "third gender" in Bangladesh, Republic of India and Pakistan

Hejira may mean:
Hejira (album), a 1976 album by Joni Mitchell
"Hejira" (song), the fifth track on the album

Hegira may mean:    

Hegira (novel), a 1979 science fiction novel by Greg Bear
The migration of humanity to the stars in Dan Simmons' Hyperion Cantos books
Hegira (Battletech), a term in the BattleTech universe

Hiigara may mean:
Hiigara, the homeworld of the Kushan, who were forced into exile after losing a war with the Taaidan. The plot of the computer game Homeworld details the return of the Kushan exiles to Hiigara. The name means "our home" in ancient Kushan language.