Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
high-flown is an adjective meaning "pretentious (especially with regard to language or ideals)". It carries 2 recorded senses.
pretentious (especially with regard to language or ideals)
“high-flown talk of preserving the moral tone of the school”
“a high-sounding dissertation on the means to attain social revolution”
colloquialism
of high moral or intellectual value; elevated in nature or style
“an exalted ideal”
“argue in terms of high-flown ideals”
“a noble and lofty concept”
“a grand purpose”
Definitions, synonyms and semantic relations for high-flown come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.