beta fish

plural beta fishes

1. Betta.

   We keep twenty beta fish at the restaurant.

   2011, Rick Tramonto, Gale Gand, Mary Goodbody, Tru: A Cookbook from the Legendary Chicago Restaurant

   2 more examples

   His chest puffed out like one of those Japanese beta fishes when it had caught a glimpse of itself in a mirror.

   2009, Duane Schwartz, Cobb's Landing

   Beta fish cannot be put together in the same bowl—because they will fight each other to the death.

   2011, Douglas Hatten, Destiny of the Tribe of Ephraim and the Restoration of the House of Israel, page 225

2. A person who is in a secondary position in a social hierarchy; a submissive person; a follower.

   And beta fish can't be beta fish if they are fighting to be alpha fish.

   2017, Lucy Loo, This Isn't a Prompt

   2 more examples

   Well, there's Winston. But he's just a beta fish, so he's stuck in the house all day either way.

   2020, Bria Quinlan, The Last Single Girl

   He had taken her for a dogsbody, a beta fish, a bridesmaid, a ride-along; he had looked right past her, as likely many people did.

   2023, Eleanor Catton, Birnam Wood, page 319