As a formalV-form pronoun,þér can have a singular or plural referent, but is always grammatically plural, similar to DanishDe, GermanSie, Frenchvous, etc. This pronoun has fallen out of everyday use, but lingers in the raw plural sense in biblical language, and finds occasional use as a V-form.
From earlierér, fromProto-Germanic*jīz, Northwest Germanic form of*jūz, fromProto-Indo-European*yúHs. The initialþ comes from a pervasivesandhi effect, triggered by word-finalð in the second person plural verb endings (e.g.hafið ér → reinterpreted ashafiðþér).