Hypoplastic

Part of speech: adjective

Definitions

1. Describing a condition in which there is inadequate development of an organ or tissue, leading to reduced function or size
2. Pertaining to a medical state characterized by the incomplete or deficient growth of specific tissues or organs
3. Referring to a medical phenomenon where certain tissues or organs exhibit underdevelopment, resulting in diminished functionality or size

Etymology: "Hypoplastic" is a modern medical coinage built from Greek parts. "Hypo-" comes from Greek "hypo", meaning "under" or "below" or "deficient", and "-plastic" comes from Greek "plastikos", meaning "moulded" or "formed", from "plassein", "to mould". Together they describe something that is formed less than it should be, rather than something that is absent or misshapen. The root "plastikos" is also behind "plastic" and "plasma" and "-plasty" in surgical terms, though those words took different paths into English. The compound itself was built by scientists and physicians writing in the 19th and early 20th centuries, when medicine was producing large numbers of new terms from classical roots to name newly described conditions. Ancient Greek physicians had no word with this exact sense, so the term is a deliberate construction rather than an inherited one.