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