partnerless

/ˈpɑːrtnərləs/
adjective
  1. Without a partner; having no companion, teammate, or spouse.
    • The partnerless player sat on the bench while the others formed teams.
    • She felt partnerless at the dance, watching everyone else pair up.
    • After his divorce, he was partnerless for several years before meeting someone new.
Antonyms