Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
perithelial is an adjective meaning "of or relating to the tissue layer around small blood vessels". It carries one recorded sense.
of or relating to the tissue layer around small blood vessels
Definitions, synonyms and semantic relations for perithelial come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.