Definition of zir in English:

zir

Pronunciation /ziər/ /zɪər/

pronoun

third person singular
  • Used instead of “him” or “her” to refer to a person of unspecified or nonbinary gender previously mentioned or easily identified.

    • ‘I handed it to zir’

possessive determiner

  • Belonging to or associated with a person of unspecified or nonbinary gender previously mentioned or easily identified.

    • ‘ze is interrupted by yet another voice from zir own past’

Origin

1990s: blend of ze and hir.