Definition of redfin shiner in US English:

redfin shiner

noun

  • Any of several North American minnows (family Cyprinidae) with fins flushed with red, especially in the breeding season; specifically (formerly) †the common shiner, Luxilus cornutus (obsolete), or (now) Lythrurus umbratilis.

Origin

Late 19th century; earliest use found in The Fitchburg Sentinel.