Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
ectomorphic is an adjective meaning "having a build with little fat or muscle but with long limbs". It carries one recorded sense.
having a build with little fat or muscle but with long limbs
Definitions, synonyms and semantic relations for ectomorphic come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.