What does endomorph mean?
An endomorph is a person whose body is characteristically soft, rounded, and heavyset. The term was introduced by American psychologist William H. Sheldon as one of three somatotypes — alongside the slender ectomorph and the muscular mesomorph — in his theory of constitutional psychology, and it derives from the fact that he linked this build to the endoderm, the embryonic layer that develops into the digestive organs. Although Sheldon's claim that body type reveals personality is now rejected by mainstream science, the word has outlived his theory and remains common in fitness and popular health writing, where it loosely denotes someone who gains weight readily and carries fat around the torso. A rarer, unrelated use appears in mineralogy, where an endomorph is a small crystal completely enclosed within a larger host crystal. The adjective is endomorphic, and the noun endomorphy names the condition itself.
nounIn the somatotypology of William H. Sheldon, a person whose body build is characterized by relative roundness and softness, with a predominance of endodermal-derived tissues such as the digestive system; more broadly, an individual with a heavyset, rounded physique.
- A person with a soft, rounded body type dominated by endodermal derivatives, per Sheldon's somatotype classification; loosely, anyone with such a physique.
- A crystal or mineral inclusion entirely enclosed within a host crystal of a different mineral (mineralogy).
"Sheldon's typology classified him as a classic endomorph, with a broad waist and rounded features."
"As an endomorph, he found that strength training suited his naturally solid frame better than distance running."
"The geologist identified a small tourmaline endomorph embedded within the quartz matrix."
Regular plural; standard in both British and American English.
"Endomorphs often excel at power-based sports where mass is an advantage."
The word literally means 'inner form' — because its coiner believed your belly came from the embryonic layer that becomes your gut.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of endomorph
Endomorph combines two Greek elements: 'endo-', meaning 'within' (as in endoderm and endocrine), and '-morph', from 'morphē', meaning 'form' or 'shape'. It was coined in the 1940s by psychologist William H. Sheldon, who named each of his three body types after the embryonic germ layer he associated with it. The same Greek root 'morphē' also underlies words such as metamorphosis and amorphous, making them etymological relatives rather than direct derivatives.
Related word forms
How endomorph is actually used
The term belongs chiefly to mid-20th-century constitutional psychology and survives mostly in fitness writing, where it is used informally to describe a body type said to gain weight easily. Because Sheldon's somatotypes are scientifically discredited as predictors of temperament, careful writers treat 'endomorph' as descriptive shorthand rather than established science. In mineralogy the term is technical and rare.
Easily confused with endomorph
An ectomorph is Sheldon's opposite type — thin, linear, and lightly built — whereas an endomorph is rounded and soft-bodied.
A mesomorph is the muscular, athletic body type in Sheldon's scheme, distinct from the rounded endomorph.