Pencilfish

Part of speech: noun

Definitions

1. A slender, small freshwater fish from South America that is named for its long, narrow body shape
2. Any of several tiny tropical freshwater fish of South America with a thin, elongated body and a flattened head
3. A small, slim-bodied fish native to South American rivers, prized by aquarium keepers for its streamlined form

Etymology: Pencilfish are small freshwater characins of South America, named for their slender, elongated bodies, which look a bit like a pencil with the fins attached. The name is a plain English compound: "pencil" plus "fish." "Pencil" itself comes from Old French "pincel," a diminutive of Latin "penicillus," meaning a little tail or brush, which was used for painting brushes and only later for the writing implement. The Latin root shares its origin with "penis" in the sense of "tail," a connection that is often noted but has nothing to do with the fish's name. The fish's name owes nothing to any actual pencil; it describes the body shape alone. The fish was named this way because the body is narrow and straight, with a flat, tapering profile that suggests the familiar writing instrument. Pencilfish are often kept in aquariums, where their slender outline and horizontal dark stripe are part of their appeal.