Middle English obsolete form of her.
Online Etymology Dictionary, © 2010 Douglas Harper
Examples from the Web for hir
The ruler, mistrustyng no deceit, answered: thou muste paie for hir.
She loked in the glasse, and was greatly displeased with hir self.
God of his mercy free hir and chase away all our divisions from hir.The Story of Paris
Sche looked upoun it, and put it in the pocket of hir goune.
They shall haue moste thanke of hir that first doth it bring.Roister Doister