runner-up

noun2

1. •
   The person who finishes second, or in any position after the first.

   • Remember, if the winner cannot complete the duties, the runner-up will take over.
2. •
   Second favourite.

   • For years, Twitter was a runner-up social media company. It never grew to the size and scale of a Facebook or an Instagram. It simply muddled along. — 2022