broadmouthed

Broadmouthed is an adjective used to describe something or someone with a wide mouth in proportion to its surroundings. The term is primarily descriptive and is not tied to a formal taxonomic rank or scientific category. It can appear as a closed compound (broadmouthed) or as a hyphenated form (broad-mouthed), with both spellings understood in general usage.

In biology, broadmouthed is commonly employed in field guides, species descriptions, and taxonomic keys to convey a notable morphological trait rather than to establish evolutionary relationships. It may describe amphibians, fishes, or other animals where the mouth opening is unusually wide relative to head size or body shape. Because it is qualitative, broadmouthed is typically used alongside other morphological descriptors such as body proportions, dentition, or jaw structure.

Beyond formal descriptions, broadmouthed can appear in common names or descriptive prose to indicate a conspicuous feature. For example, field guides or regional accounts may reference “broadmouthed” species to help observers identify specimens in the field. The term is likewise found in literary or journalistic contexts as a vivid, nontechnical way to characterize faces or expressions, such as a broadmouthed grin, though such usage is informal.

See also: mouth morphology, descriptive taxonomy, compound adjectives.