There are multiple origins and translations for the name Hagar:
1. Hebrew (הגר) which actually means - "migrate, immigrate, emigrate; fugitive".
Hagar according to the Abrahamic faiths, was the second wife of Abraham, and the mother of prophet of Allah Ismail, Her story is recorded in the Book of Genesis, mentioned in Hadith, and alluded to in the Qur'an. Hagar's son, Ishmael, is the patriarch of the Ishmaelites.
2. Derivative form of the Arabic name Hijra semantics - "migration of the prophet Muhammad".