Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
astronomic is an adjective meaning "relating or belonging to the science of astronomy". It carries 2 recorded senses.
inconceivably large
Definitions, synonyms and semantic relations for astronomic come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.