From Longman Dictionary of Contemporary Englishthe vanity of somethingthe vanity of somethingliteraryUNIMPORTANT the lack of importance of something compared to other things that are much more important → vanity
Examples from the Corpus
the vanity of something• Instead, he had directed his talents to bolstering the vanity of the military and the higher-paid members of the Civil service.• She blinked artificial eyelashes over wide, brown eyes that were smarting from the vanity of contact lenses.• By using key lines as verbal motifs, Pimlott also turns the play into a sombre meditation on the vanity of power.• Herodotos here shakes his head over the vanity of human wishes.• For conservatives it represented the vanity of social engineering and the breakdown of the liberal state in the face of impossible demands. 