Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
arc-boutant is a noun meaning "a buttress that stands apart from the main structure and connected to it by an arch". It carries one recorded sense.
a buttress that stands apart from the main structure and connected to it by an arch
Definitions, synonyms and semantic relations for arc-boutant come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.