Waterdog

Part of speech: noun

Definitions

1. An aquatic salamander that keeps its gills throughout life and lives entirely in water, especially a North American species of the genus Necturus
2. A amphibian of the mudpuppy kind that retains feathery external gills and never leaves its watery habitat as an adult
3. A fully aquatic salamander with external gills that remains in streams and lakes rather than moving onto land as it matures

Etymology: Waterdog is a plain compound: "water" joined to "dog," with no hidden history behind it. The name is applied to the gilled water salamander, an aquatic amphibian that keeps its external gills into adulthood, which is the feature that makes it look like a creature that has never left the water. The "dog" element is the one worth a second look. English has long used "dog" in names for animals that are not canines, usually to suggest a sturdy, scrappy, or ungainly creature, as in "prairie dog" or "sea dog." Here it suggests a squat, heavy-bodied animal that swims and lingers in streams and lakes rather than a dog in any literal sense.

Synonyms: mudpuppy