high-sounding vs high-flown

high-sounding and high-flown both are adjectives.

Word	Noun	Adjective	Verb	Adverb
high-sounding	No	Yes	No	No
high-flown	No	Yes	No	No

As adjectives, high-sounding and high-flown are synonyms defined as:

high-sounding and high-flown: pretentious (especially with regard to language or ideals)

Other synonyms of high-sounding include inflated.

high-sounding (adjective)	high-flown (adjective)
pretentious (especially with regard to language or ideals)	of high moral or intellectual value; elevated in nature or style
	pretentious (especially with regard to language or ideals)