ectomorphic

[ ek-tuh-mawr-fik ]
/ ˌɛk təˈmɔr fɪk /

adjective

having a thin body build, roughly characterized by the relative prominence of structures developed from the embryonic ectoderm (contrasted with endomorphic, mesomorphic).

Origin of ectomorphic

First recorded in 1935–40; ecto- + -morphic
Related formsec·to·morph·y, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019