Unless you’re about to sit down to dinner, catfish is usually used as a slang term for a hoax perpetrated with a fake online identity.
Urban Dictionary defines “catfish” as “ someone who pretends to be someone they’re not using Facebook or other social media to create false identities, particularly to pursue deceptive online romances.”
The term originated from the 2010 documentary “Catfish,” which followed a guy named Nev pursuing a Facebook romance with a young woman named Megan. When Nev goes to meet her, however, he discovers that “Megan” was a fictional character created by her mother. Nev hears a story about how live cod shipped from Asia to North America used to arrive mushy because they were inactive in the tanks. Fishermen discovered putting catfish in with the cod kept them active. People like Angela are “catfish,” because they keep other people active in life.
The MTV reality show, “Catfish,” follows that theme in bringing together online couples who’ve never met to discover if either is a “catfish.”
Or if you really are just talking about food, catfish are a ray-finned fish found on all continents but Antarctica.