A heavy person with a soft and rounded body

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Endomorph \En"do*morph\, n. [Endo- + Gr. morfh` form.] (Min.) A crystal of one species inclosed within one of another, as one of rutile inclosed in quartz. [1913 Webster] ||

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1940 as one of W.H. Sheldon's three types of human bodies, from endo- + -morph , from Greek morphe "form" (see Morpheus ). Earlier, "a mineral encased in the crystal of another mineral" (1874). Related: Endomorphic .

WordNet Word definitions in WordNet
n. a heavy person with a soft and rounded body

Wiktionary Word definitions in Wiktionary
n. 1 A mineral, especially a crystal, enclosed within another 2 A person of the endomorphic physical type characterised by big bones, round face, large trunk and thighs and a naturally high degree of body fat, especially around the midsection. Endomorphs ...