A small fish that appears or is caught during winter, or a fish species that survives in very cold water.
A compound word from 'frost' and 'fish,' likely a regional or colloquial term for fish found in winter conditions. Similar compound patterns appear in names like 'catfish' and 'dogfish.'
Some fish actually thrive under ice—they have special antifreeze-like proteins in their blood that let them survive in waters that would kill most other animals, which is why cold-water fish are biological marvels.
Complete word intelligence in one call. Free tier — 50 lookups/day.