high-flown

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”

of high moral or intellectual value; elevated in nature or style

• “an exalted ideal”
• “argue in terms of high-flown ideals” Oliver Franks
• “a noble and lofty concept”
• “a grand purpose”